JP2999308B2 - Method for producing imidazoline having ester group - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a good odor and hue,
The present invention also relates to a method for producing imidazoline having an ester group capable of imparting excellent flexibility to fibers.

[0002]

2. Description of the Related Art In recent years,
As a softener base, those excellent in various properties such as safety, low irritation to skin, biodegradability, etc. in addition to surface activity are demanded. An imidazoline having a substituent is known as satisfying these properties to some extent (BP 1,565,808). As a method for producing an imidazoline having an ester group as a substituent (hereinafter referred to as an ester imidazoline), Japanese Patent Application Laid-Open No. 2-1479 describes that a monosubstituted imidazoline is reacted with an esterifying agent under high vacuum conditions. I have. As a method for producing an ester imidazoline, JP-A-2-242973 discloses that
When a mono-substituted imidazoline is reacted with an esterifying agent (fatty acid or ester thereof) and an esterification catalyst at a high temperature and a normal pressure under an inert gas sparging or under a vacuum of 0.2 mmHg to 2 mmHg, the ester imidazoline can be obtained in high yield Is obtained. However, in the methods described therein, ester imidazolines can be obtained in high purity, i.e., with reduced unreacted monosubstituted imidazoline content and unreacted esterifying agent content, at elevated temperatures for extended periods of time. A reaction was required, and deterioration of the hue and odor of the reaction product accompanying thermal deterioration was inevitable. An object of the present invention is to provide an ester imidazoline having good hue and odor.

[0003]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have found that an ester imidazoline having good hue and odor can be obtained by employing a specific method. Was completed.
That is, the present invention has the general formula (1)

[0004]

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(Wherein R ¹ is a straight-chain or branched-chain C 7 -C 7)
21 alkyl or alkenyl groups, R ² has 2 or 3 carbon atoms
Represents an alkylene group. ) And imidazoline,
Formula (2) R ³ CO ₂ R ⁴ (2) (wherein, R ³ is a straight-chain or branched-chain alkyl or alkenyl group having 7 to 21 carbon atoms, and R ⁴ is a straight-chain or branched-chain carbon number. 1 to
5 represents an alkyl group. After reacting with the fatty acid ester represented by the general formula
Unreacted imidazoline represented by (1) and / or general formula
(2), characterized by removing the unreacted fatty acid ester from the reaction mixture using a thin film evaporator,
General formula (3)

[0006]

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(Wherein, R ¹ , R ² , and R ³ have the same meanings as described above). A method for producing an imidazoline having an ester group represented by the formula:

Hereinafter, the present invention will be described in detail. <Esterification step> The general formula (1) used in this step
As the alkyl group or alkenyl group at the 2-position of imidazoline represented by (R ¹ ), for example, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, coconut fatty acid, tallow fatty acid, an alkyl or alkenyl group derived from palm fatty acid, etc., and, as a 1-position hydroxyalkyl groups (-R ² OH) is
Examples include a 2-hydroxyethyl group, a 3-hydroxytrimethylene group, and a 2-hydroxypropyl group. Examples of the fatty acid ester represented by the general formula (2) include, for example, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid,
Examples thereof include methyl esters, ethyl esters, and propyl esters of fatty acids such as coconut fatty acid, tallow fatty acid, and palm fatty acid. In the reaction of the present invention, the general formula
The molar ratio of the imidazoline represented by (1) to the fatty acid ester represented by the general formula (2) is preferably fatty acid ester / imidazoline = 0.3 to 3.0, more preferably 0.8 to 2.0.
Range. If the molar ratio is out of these ranges, a large amount of unreacted raw materials to be removed remains in the reaction mixture after the reaction, which is not preferable.

In this step, the imidazoline (1) and the fatty acid ester (2) may be reacted without a catalyst.
An esterification catalyst may be used. Examples of the esterification catalyst include tetramethyl titanate, tetraethyl titanate, tetraisopropyl titanate, and tetra-titanate.
n-butyl, titanium tetrachloride, titanium tetrabromide, sodium methylate, sodium ethylate, sodium propylate, sodium tert-butylate, potassium methylate, potassium ethylate, potassium propylate, potassium tert-butylate, acetic acid Stannous, stannous hydroxide, stannous bromide, stannous chloride, stannous fluoride, stannous iodide, stannous oxychloride, stannous sulfate, stannous oxide, laurin Stannous acid, stannous octoate, stannous oleate, stannous oxalate, stannous butoxide, stannous-2-ethylhexoxide, stannous phenoxide, stannous crezoxide, chloride Ditin, stannic bromide, stannic fluoride, stannic oxychloride, etc., and the amount used is based on the number of moles of imidazoline represented by the general formula (1). On the other hand, it is 0.1 to 20 mol%, more preferably 1 to 10 mol%.

In this step, unreacted fatty acid ester (2) and / or unreacted imidazoline (1) in the reaction mixture
The reaction rate is high up to 2 to 10% by weight (hereinafter referred to as unreacted raw material), and thereafter the reaction rate becomes extremely slow, and the unreacted raw material in the reaction mixture, which can be regarded as substantially the end point of the reaction, is 2% by weight. It takes a very long time to react to less than%. In addition, when the reaction is carried out for a long time until a substantial end point of the reaction, deterioration of the hue and odor of the reaction product due to thermal deterioration is inevitable. However, when the amount of the unreacted raw material in the reaction mixture is 2 to 10% by weight, deterioration of the hue and odor in the reaction mixture has hardly occurred yet. At this point, the reaction is stopped by cooling at this point, and then the unreacted raw materials in the reaction mixture are distilled off using a thin film evaporator.
By adjusting the amount to less than 10% by weight, high-purity ester imidazoline (3) having good hue and odor can be obtained. The reaction time can be reduced by such a method of the present invention,
Productivity can also be greatly improved.

In this step, the reaction between the imidazoline (1) and the fatty acid ester (2) is carried out at a temperature of 100 to 200 ° C., preferably 120 to 180 ° C. If the temperature is lower than 100 ° C., the time required for the unreacted raw materials to reach 2 to 10% by weight is extremely long, and the productivity is significantly reduced. On the other hand, when the temperature is higher than 200 ° C., the reaction time can be shortened, but the deterioration rate of the hue and odor is large, and the deterioration of the hue and odor of the reaction product is inevitable. In this step, the reaction pressure may be any of a range from a pressurized pressure to a reduced pressure. However, since the esterification is a dealcoholization reaction, the reduced pressure increases the reaction rate and requires a shorter reaction time. Specifically, 5-20
The pressure is 0 mmHg, more preferably 10 to 100 mmHg. If the value is smaller than this, the fatty acid ester (2) may be removed to the outside of the reaction system, and if the value is larger, the unreacted fatty acid ester (2) and unreacted imidazoline (1) remain more, Not preferred. Further, since the hue is significantly degraded by contact with oxygen, it is desirable to carry out the reaction under a flow of an inert gas such as nitrogen, carbon dioxide, helium, neon, or argon. When an esterification catalyst is used after the completion of the esterification reaction in this step, the catalyst activity may be eliminated by a neutralization reaction, or the catalyst activity may be eliminated by adsorbing the catalyst on activated clay or the like.

<Unreacted raw material removing step> In the method of the present invention, the unreacted raw material is removed using a thin film evaporator. The operating temperature is 100 ~ 200 ℃,
At a temperature higher than 200 ° C, the color degradation and odor degradation due to thermal decomposition of ester imidazoline (3) become severe,
On the other hand, if the temperature is lower than 100 ° C., the efficiency of removing unreacted raw materials decreases. The operating pressure is preferably 100 mmHg or less. On this occasion,
In order to improve the efficiency of removing unreacted raw materials, steam or an inert gas may be blown into the thin-film evaporator. At this time, it is effective to flow a steam or an inert gas stream in any form of countercurrent, cocurrent or crossflow with respect to the ester imidazoline (3) on which the thin film is formed. The inert gas may be any gas which does not react with the ester imidazoline (3), and is preferably an inert gas such as nitrogen or carbon dioxide .

The thickness of the thin film is preferably as thin as possible, but is not particularly limited, and it is sufficient that the thickness can be obtained with a commercially available thin film evaporator, but usually it is preferably about 10 mm or less. The Reynolds number of the thin film formed during operation is 2
It is preferably not less than 0,000. As an apparatus for forming a thin film, a normal thin film evaporator can be used. For example,
Examples include a Smith-type thin film evaporator (manufactured by Shinko Faudler Co., Ltd.), a Hitachi control device (manufactured by Hitachi, Ltd.), and a lure thin-film evaporator (manufactured by Luwa). These are all devices for forcibly forming a thin film, but a device for forming a natural thin film such as a falling thin film type can also be used. The batch distillation method of distilling off unreacted fatty acid ester (2) and / or unreacted imidazoline (1) while supplying steam or an inert gas into the reaction mixture has a large heat history. ) And / or unreacted imidazoline (1) is not preferred because ester imidazoline (3) may be degraded by heat.

[0014]

Next, the present invention will be described in detail with reference to examples, but the scope of the present invention is not limited by these examples.

[0015] Example 1 stirrer, a thermometer, a dropping funnel, 1 liter -4-necked flask equipped with a distillation column, 1-hydroxyethyl-2-f
Heptadecyl imidazoline 352 g (1 mole) were charged methyl stearate 298 g (1 mol), heated at 80 ° C. (melting). Then, the temperature is raised to 150 ° C. Reaction system is 150
After the temperature reached 4.8 g (25 mmol) of a 28% methanol solution of sodium methylate as an esterification catalyst was added dropwise. After the addition of the catalyst, the pressure in the reaction system is reduced to 20 mmHg. In this state (150 ° C., 20 mmHg), the reaction was carried out for 2 hours to perform an activated clay treatment. The obtained reaction mixture was kept at 70 ° C., and the evaporation area was 0.
Flow rate 0.6 l / hr, temperature 1 in 034 m ² thin film evaporator
The mixture was fed at 80 ° C. and a pressure of 0.2 mmHg to obtain a low boiling point of 25% by weight. The compositions after the reaction and after the distillation were as shown in Table 1, respectively. The hue and odor of the reaction product were Gardner 2 and ○, respectively, which reached usable levels. The hue of the reaction product was measured with a Gardner colorimeter, and the odor was evaluated by a sensory test. ：: good without specific odor X: Specific smell is bad.

Examples 2 to 4 1-hydroxyethyl-2- hepta at a molar ratio shown in Table 1.
Decyl imidazoline and methyl stearate were charged and reacted at the temperature and pressure conditions shown in Table 1, respectively. Subsequently, the obtained reaction product was placed in a thin-film still having an evaporation area of 0.034 m ^{2 at} a flow rate of 0.6 liter / hr. It was supplied under the conditions of temperature and pressure shown in Table 1. The low-boiling fraction, the composition at the end of the reaction and the composition after distillation were as shown in Table 1, respectively. Both the hue and odor of the reaction product were Gardner 2-3 and O, respectively, and reached a usable level.

Comparative Example 1 1-Hydroxyethyl-2- heptadene was prepared in the same manner as in Example 1.
Charged sill imidazoline 352g (1 mole) and methyl stearate 298 g (1 mol) in 4-necked flask 1 liter of sodium methylate 28% methanol solution of an esterification catalyst at 0.99 ° C. 4.8 g (25 mmol) dropwise Then, the reaction was carried out for 24 hours under the same conditions as in Example 1 (150 ° C., 20 mmHg) to perform an activated clay treatment. Unreacted methyl stearate in the reaction product was 0.5% by weight, and the reaction was considered to be almost complete. The hue and odor of the reaction product were Gardner 5 to 6 and ×, respectively, and were unusable.

Comparative Example 2 The same sample as in Example 3 was subjected to batch distillation at the temperature and pressure shown in Table 1. The hue and odor after distillation were Kardner 7 and ×, respectively, and were unusable.

[0019]

[Table 1]

[0020]

According to the present invention, ester imidazoline (3) having extremely excellent hue and odor can be obtained with high purity and high production efficiency.

Claims (3)

(57) [Claims] [Claim 1] General formula (1) (Wherein, R ¹ represents a straight-chain or branched-chain alkyl or alkenyl group having 7 to 21 carbon atoms, R ² represents an alkylene group having 2 or 3 carbon atoms), and a general formula ( 2) R ³ CO ₂ R ⁴ (2) (wherein, R ³ is a straight-chain or branched-chain alkyl or alkenyl group having 7 to 21 carbon atoms, and R ⁴ is a straight-chain or branched-chain carbon group having 1 to 1 carbon atoms.
5 represents an alkyl group. After reacting with the fatty acid ester represented by the general formula
Unreacted imidazoline represented by (1) and / or general formula
(2), characterized by removing the unreacted fatty acid ester from the reaction mixture using a thin film evaporator,
General formula (3) (Wherein, R ¹ , R ² , and R ³ have the same meanings as described above). 2. A reaction mixture obtained by reacting an imidazoline represented by the general formula (1) with a fatty acid ester represented by the general formula (2), wherein the reaction mixture is present in the reaction mixture.
The content of the unreacted imidazoline represented by the general formula (1) and / or the unreacted fatty acid ester represented by the general formula (2) is 2 to 2.
The method for producing imidazoline having an ester group according to claim 1, which is 10% by weight. 3. A reaction between an imidazoline represented by the general formula (1) and a fatty acid ester represented by the general formula (2), followed by the reaction represented by the general formula (1) present in the reaction mixture. An unreacted imidazoline and / or an unreacted fatty acid ester represented by the general formula (2) is removed from the reaction mixture using a thin film evaporator, and the ester group represented by the general formula (3) is obtained. The content of the unreacted imidazoline represented by the general formula (1) and / or the unreacted fatty acid ester represented by the general formula (2) in the imidazoline having a content of less than 2% by weight. A method for producing an imidazoline having an ester group.