JPS6149308B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing high quality imidazoline compounds from diamines, higher fatty acids, and esters thereof.

Although imidazoline itself is insoluble in water, it is uniformly dispersed in water, and its mixture has excellent foaming power. In addition, the derivative is water-soluble, and its aqueous solution not only has excellent detergency and foaming power as an amphoteric active agent, but also has extremely low skin irritation. Therefore, it is useful as shampoo, kitchen, and clothing detergents, as well as emulsifiers and cosmetic bases, and as demand is expected to grow in the future, an efficient method for producing high-quality imidazoline compounds is needed. It is hoped that it will appear.

Conventionally, as a method for producing imidazoline compounds by reacting higher fatty acids and diamines, there is a method disclosed in, for example, Industrial Chemistry Magazine, Vol. 68, No. 11, 1965, p. 186. It was adopted in According to this method, xylene is added, water produced is removed by azeotropy, and after the reaction, xylene is distilled off to obtain an imidazoline compound. The fundamental drawback of this method is that it is difficult to completely remove xylene, and the resulting reaction product has an odor and cannot be used in various household cleaning products such as shampoo and kitchen detergent. This was used for the Motsubara industry.

Manufacturing methods that have improved this quality defect include, for example, the method disclosed in British Patent No. 985321 and the method disclosed in Japanese Patent Publication No. 36235/1983. The former method involves stirring the raw materials in a reactor while introducing nitrogen gas and reacting while distilling off the distillate, but it has the drawback that the achieved reaction rate is very low. In the latter method, the reaction is carried out in a reactor while gradually changing the reaction temperature and pressure, and the diamine is continuously added in an amount that is distilled out during the reaction, and the reaction is completed for several hours. It is. This method is excellent in terms of achieving a high reaction rate, but from the viewpoint of reaction operation, (a) operations regarding reaction temperature and pressure are complicated throughout the long reaction period, and in fact,
It is difficult to expect reproducibility; (b) it is practically difficult to measure the amount of distilled diamine and continuously add new diamine; (c) the distilled diamine contains various by-products. Since it contains living organisms, it cannot be reused in the imidazolination reaction, and its disposal is problematic.

Conventionally, the imidazolination reaction itself has a very slow reaction rate, and in order to increase the reaction rate achieved, strict conditions and complicated operations are required. Therefore, an efficient manufacturing method was desired.

The present inventors have overcome the drawbacks of the above conventional methods,
In order to develop a method to efficiently produce high-quality imidazoline compounds with a high reaction rate, low acid value, and low degree of coloration using simple operations, we have developed a method for efficiently producing diamines and imidazoline compounds. It has been found that good results can be obtained when a reactor charged with a mixture of a higher fatty acid and its ester is heated and reacted in a completely closed state, unlike conventional methods.

This should be a completely unexpected fact considering the common sense of the prior art, which is based on distilling water, alcohol, and diamine from the reaction system.

Until now, there has been no literature suggesting this fact, and the present inventors were able to accomplish the present invention only by arriving at this fact.

That is, the present invention provides a diamine represented by the general formula _H2N - _CH2CH2 - _NHR '(R' represents an alkylol group having 2 to 4 carbon atoms) and a diamine represented by the general formula RCOOH (R is a carbon atom (representing an alkyl group or alkenyl group of number 8 or more) or its methyl ester, ethyl ester, or glycerin ester are reacted, and the general formula In producing the imidazoline compound represented by (R and R' have the same meanings as above), the mixture of the diamine and higher fatty acid is heated at an internal temperature of 100 to 220°C, preferably 120 to 210°C, and Provided is a method for producing an imidazoline compound, characterized in that water, alcohol and excess diamine are removed by distillation after the reaction without substantially distilling off the water, alcohol and diamine in the reaction system. It is.

The structure of the present invention will be explained in detail below. Examples of the diamine used in the present invention include NH ₂ C ₂ H ₄ NHC ₂ H ₄ OH NH ₂ C ₂ H ₄ NHC ₃ H ₆ OH. can.

Further, examples of higher fatty acids represented by the above general formula include caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, nonadecanoic acid, coconut fatty acid (mainly containing lauric acid), Examples include hydrogenated bovine fatty acids (mainly containing stearic acid) and their methyl esters, ethyl esters, and glycerides.

The ratio of both is the amount of diamine to fatty acid,
A slight stoichiometric excess is preferred;
The molar ratio of diamine to fatty acid is preferably 1.01 or more, more preferably 1.03 or more.

Naturally, this diamine, higher fatty acid and its ester are continuously supplied in the same ratio in the continuous reactor.

What is important in the present invention is that the reaction system is heated at 100 to 220°C.
Preferably, it is heated to 120 to 210°C to carry out the imidazolination reaction, and at that time, the produced water, alcohol, and excess diamine are kept in the reaction system.

This "substantially suppressed" means that it is acceptable even if there is a small amount of leakage that is accompanied by only slight fluctuations in the system due to the equipment.

Such reaction systems are usually formed in closed, pressure-resistant reactors, such as tank autoclaves, tube reactors, etc., whether batchwise or continuously.
A substantially closed system may be formed in the device by appropriate means. In other words, this reaction system is the same as carrying out this reaction in the presence of water, alcohol, and excess diamine to be produced. Typically, the pressure in the reaction vessel of the present invention is between 3 and 20 atmospheres. This pressure is determined by the vapor pressure at the internal temperature of the produced water, alcohol and diamine system.

The reaction system of the present invention is defined by the above-mentioned conditions. For example, if the reaction system is carried out under open conditions, which are outside the conditions of the present invention, the water, alcohol, and diamine produced will be released outside the reaction system. The distillation and reaction system does not maintain the specified molar ratio of diamine and fatty acid, making it impossible to achieve a high reaction rate, and also making it impossible to maintain the desired temperature due to evaporation of the water, alcohol, and diamine produced. This would cause problems and would not provide the simple approach and high efficiency of the present invention.

In the present invention, the temperature of the reaction system is 100-220°C, preferably 120-210°C. If the temperature is less than 100°C, the reaction rate is low and a satisfactory reaction rate cannot be achieved. Furthermore, if the temperature exceeds 220°C, thermal decomposition and oxidation of the reactants occur, causing coloring of the reaction products and generation of off-odor.

The reaction time required for the reaction system in the present invention is such that the higher fatty acids and their esters in the system are reduced to 5% or less of the initial value as the reaction progresses.
It takes 0.5 to 2 hours. Even if you include the time it takes for the reaction system to reach a more stable state, it will take about 1 to 2.5 hours. This short reaction time is also an advantage of the present invention. Considering that the conventional method required approximately 5 to 9 hours, it can be seen that the present invention is extremely superior.

Next, the reaction system is transferred to a step of distilling off the produced water, alcohol, and excess diamine. This process typically includes a depressurization step. This is because distillation under reduced pressure under heating is commonly used, so most of the produced water and alcohol are distilled off at the stage of depressurization.

Next, the pressure is further reduced to distill off the diamine remaining in the reaction system. The temperature at this time is approximately 170 to 220
℃ and the pressure is 5 to 50 mmHg, the required time is sufficient for 0.5 to 2 hours. Considering that in the prior art, topping of the reactant was necessary and the time was similar, the present invention provides a method for the first step in which the reaction system is not depressurized. It can be understood that the difference in reaction time of the reaction system means the effect of the technology, that is, the difference.

It is not yet clear why the method of the present invention was able to obtain a high quality product in a short time, unlike the conventional method.

As described above, according to the method of the present invention, it is possible to successfully produce an imidazoline compound from a diamine, a higher fatty acid, and an ester thereof, which was previously thought to be extremely difficult. Moreover, the operation is extremely simple compared to conventional methods, and from this point of view it is suitable for industrial implementation, and the use of a continuous reactor in the present invention also allows for a flashing step to be added in the middle. It also has advantages that can be achieved easily.

The content of imidazoline compounds in the reaction product obtained by the method of the present invention is sufficiently high, 85%
As described above, it can be used as is as a high-quality imidazoline compound for various purposes without requiring post-treatment.

Next, the present invention will be explained in more detail based on examples.

Example 1 In a 1-volume reaction flask equipped with a stirrer, thermometer, sample extraction tube, condenser and pressure gauge, 400 g of coconut fatty acid (MW = 200) and aminoethylethanolamine (abbreviated as AEEA, MW =
104), and the molar ratio of diamine to higher fatty acid was 1.05.

Next, this was sealed and heated to about 200°C for 2 hours to carry out a reaction. During this time, a sample was taken from the reaction mixture after a predetermined period of time and the acid value was measured.The acid value was 40 at 0.5 hours, 12 and 1.5 at 1 hour.
8 hours later, it dropped to 6 in 2 hours. When the acid value reaches around 5, open the valve installed between the condenser and reaction flask communication tube to release the pressure in the reaction flask, and then use a vacuum pump to increase the pressure to 30 mmHg to remove excess diamine. I distilled it out. This treatment takes one hour, during which time the acid value decreases to
It dropped to 1.8.

When the diamine stopped distilling out, heating was stopped, the reaction mixture was cooled, and its properties were measured.
In this way, a product with an imidazoline content of 87% by weight and an acid value of 1.8 was obtained.

Example 2 A reaction was carried out in the same manner as in Example 1 except that the molar ratio of AEEA to coconut fatty acid was 2.0.
After reacting for 1.5 hours, the acid value decreased to 5, so the reaction was stopped and topping treatment was performed for 1 hour at a pressure of 30 mmHg and a temperature of about 190°C.

In this way, imidazoline content 86% by weight,
A product with an acid value of 0.9 was obtained.

Example 3 A reaction was carried out in the same manner as in Example 1 except that the molar ratio of AEEA to coconut fatty acid was 4.0.
After 1 hour, the acid value decreased to 6, so the pressure was increased to 35 mm.
Topping treatment was performed for 2 hours at a temperature of about 190° C. with Hg.

In this way, imidazoline content 91% by weight,
A product with an acid value of 0.6 was obtained.

Example 4 The reaction was carried out in the same manner as in Example 1 except that the reaction temperature was maintained at 180 to 185°C and the reaction was carried out for 2.5 hours, and then at a pressure of 30 mmHg and a temperature of about 185°C,
Topping treatment was performed for 1 hour. In this way, a product with an imidazoline content of 85% by weight and an acid value of 1.9 was obtained.

Comparative Example In the same manner as in Example 1, the reaction was carried out at about 140°C for 3 hours, and when the acid value was 34, topping treatment was carried out at a pressure of 32 mmHg and a temperature of 190°C for 1 hour.

In this way, imidazoline content 73% by weight,
A product with an acid number of 17 was obtained.

Claims (1)

[Claims] 1 A diamine represented by the general formula H ₂ N—CH ₂ CH ₂ —NHR′ (R′ represents an alkylol group having 2 to 4 carbon atoms) and a diamine represented by the general formula RCOOH (R is a carbon (representing an alkyl group or alkenyl group having 8 or more atoms) or its methyl ester, ethyl ester, or glycerin ester is reacted, and the general formula (R and R' have the same meanings as above) When producing the imidazoline compound represented by A method for producing an imidazoline compound, which comprises reacting water, alcohol, and diamine without distilling them out, and then removing water, alcohol, and excess diamine. 2. The method according to claim 1, wherein the internal temperature is 120 to 210°C.