JP2999306B2 - 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 relates to a method for producing an imidazoline having an ester group, which is useful as a fabric softener base. More specifically, the present invention relates to a method for producing the imidazoline having a good hue and odor in a high yield while suppressing by-products such as an amine having an amide group.

[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, Japanese Patent Application Laid-Open No. 2-1479 describes that a monosubstituted imidazoline is reacted with an esterifying agent under high vacuum. As a method for producing the imidazoline, JP-A-2-242973 discloses a method using a mono-substituted imidazoline, an esterifying agent and an esterification catalyst under an inert gas sparging at a high temperature and a normal pressure, or a pressure of 0.2 mmHg to 2 mmHg. It is described that the reaction under vacuum can give the imidazoline in high yield. However, it is not easy to actually produce the imidazoline in a high yield by the methods described therein, and it was not possible to obtain the imidazoline having a more favorable hue and odor.

[0003]

Means for Solving the Problems In view of the above situation, the present inventors have conducted intensive studies on a method for producing imidazoline having an ester group. As a result, the present inventors have found that an ester group having a good hue and odor can be obtained in a high yield. A method for producing imidazoline having the same has been found, and the present invention has been 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 an imidazoline compound represented by the general formula (2) R ³ CO ₂ R ⁴ (2) (wherein R ³ is a linear or branched alkyl or alkenyl group having 7 to 21 carbon atoms, R ⁴ Represents an alkyl group or a hydroxyalkyl group having 1 to 5 carbon atoms) under the reduced pressure condition while introducing an inert gas into the reaction system in the presence of an esterification catalyst. General formula (3)

[0006]

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(Wherein, R ¹ , R ² , and R ³ have the same meanings as described above). The present invention provides a method for producing an imidazoline having an ester group represented by the following formula (hereinafter referred to as ester imidazoline). Examples of the 2-position alkyl group or alkenyl group (R ¹ ) of the imidazoline compound represented by the general formula (1) used in the present invention include caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, Stearic acid, behenic acid, coconut fatty acid, tallow fatty acid, an alkyl group or alkenyl group derived from palm fatty acid,
As the 1-position of the hydroxyalkyl group (-R ² OH), 2-hydroxyethyl group, 3-hydroxytrimethylene group, 2-hydroxypropyl group and the like. As the fatty acid ester represented by the general formula (2), for example, caprylic acid, capric acid, lauric acid,
Examples thereof include methyl esters, ethyl esters, and propyl esters of fatty acids such as myristic acid, palmitic acid, stearic acid, behenic acid, coco fatty acid, tallow fatty acid, and palm fatty acid. In the reaction of the present invention, the molar ratio of the imidazoline compound represented by the general formula (1) to the fatty acid ester represented by the general formula (2) is preferably fatty acid ester / imidazoline compound = 0.3 to 2.0, more preferably It is in the range of 0.8 to 1.5.

The esterification catalyst used in the present invention includes Ti (OR ⁵ ) ₄ , TiX ₄ , NaOR ⁶ , KOR ⁶ , SnY ₂ , SnY ₄ , SnO and SnOZ (in each formula, R ⁵ is the number of carbon atoms. X is a halogen atom, X is a halogen atom, R ⁶ is an alkyl group having 1 to ⁶ carbon atoms, Y is an alkyl group having 1 to 8 carbon atoms, a hydroxyalkyl group, a halogen atom, a hydroxy group, an inorganic acid residue, An organic acid residue or a fatty acid residue, and Z represents an alkyl group or an aryl group.)
Preferred are at least one selected from the group consisting of, for example, tetramethyl titanate, tetraethyl titanate, tetraisopropyl titanate, tetra-n-butyl titanate, titanium tetrachloride, titanium tetrabromide,
Sodium methylate, sodium ethylate, sodium propylate, sodium-t-butylate, potassium methylate, potassium ethylate, potassium propylate, potassium-t-butyrate, stannous acetate, stannous hydroxide, bromide Stannous, stannous chloride, stannous fluoride, stannous iodide, stannous oxychloride, stannous sulfate, stannous oxide, stannous laurate, stannous octoate, oleic acid Stannous, stannous oxalate,
Stannous butoxide, stannous-2-ethylhexoxide, stannous phenoxide, stannous crezoxide, stannic chloride, stannic bromide, stannic fluoride, stannic oxychloride and the like It is used in an amount of 0.1 to 20 with respect to the number of moles of the imidazoline compound represented by the general formula (1).
Mol%, more preferably 1 to 10 mol%.

The inert gas used in the present invention includes at least one selected from the group consisting of nitrogen, helium, neon and argon, and is represented by the general formula (1) used in the reaction. Imidazoline compounds and general formulas
Per kg of the total weight of the fatty acid ester represented by (2),
The inert gas is introduced into the reaction system at a rate of 0.01 to 50 l / hr, more preferably 5 to 20 l / hr. Even when the inert gas is used at a ratio less than this range, an ester imidazoline having a good hue and odor cannot be obtained. There is no merit in the quality of the ester imidazoline as compared with the case where an inert gas is used, and this is disadvantageous in the production economics of the ester imidazoline. Further, in the present invention, it is important to bring the reaction system under reduced pressure simultaneously with the introduction of the inert gas into the reaction system.
It is preferably 0 mmHg, more preferably in the range of 10 to 100 mmHg. If the numerical value of the degree of decompression is below this range, the general formula
The fatty acid ester represented by (2) is not preferable because it may be removed to the outside of the reaction system. When the value of the degree of reduced pressure exceeds this range, the yield of the target ester imidazoline decreases.

[0010] The reaction temperature of the reaction system of the present invention is 100 to 200 ° C.
The reaction is carried out under conditions such that the short-chain alcohol R ⁴ OH obtained by the reaction (where R ⁴ has the above-mentioned meaning) is removed from the reaction system. . The ester imidazoline represented by the general formula (3) obtained by the method of the present invention is useful as a softener for fibers and the like, and has good hue and odor.

[0011]

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.

Example 1 1-octadecyloyloxyethyl-2-heptadecyl
Synthesis of imidazoline In a 2-liter 4-neck flask equipped with a stirrer, thermometer, dropping funnel, distillation column, and gas inlet tube, 352 g (1 mol) of 1-hydroxyethyl-2-heptadecylimidazoline, methyl stearate Charge 298g (1 mol)
Heat (melt) at 80 ° C. Then, the temperature is raised to 150 ° C. After the temperature of the reaction system reached 150 ° C, 4.8 g of a 28% methanol solution of sodium methylate (25 mm
ol) Add dropwise. 6.5 liters / hr of nitrogen gas after catalyst dripping
(10 liters / hr · kg) while reducing the pressure of the reaction system to 20 mmHg. Continue this state (150 ° C, 20mmHg)
The remaining amount of 1-hydroxyethyl-2-heptadecylimidazoline was confirmed every hour by gas chromatography. Two hours after the dropwise addition of the catalyst, 1-hydroxyethyl-2-
After confirming that the concentration of heptadecyl imidazoline in the system was 1%, the reaction was terminated. Analysis of this reaction product by gas chromatography revealed that 95% by weight of 1-octadecyloyloxyethyl-2-heptadecylimidazoline (having the following structural formula (4)) was formed. When 1-octadecyloyloxyethyl-2-heptadecylimidazoline obtained here was immediately smelled, there was no specific smell, and the hue was Gardner 3 at this time.

[0013]

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Examples 2 and 3 The reaction was carried out in the same manner as in Example 1 except that the reaction temperature, the esterification catalyst, the pressure of the reaction system, the type and the flow rate of the inert gas were changed. Table 1 shows the reaction conditions and the evaluation results of the composition, hue, and odor of the reaction product together with Example 1.
Shown in

Comparative Example 1 An ester imidazoline synthesis method described in Japanese Patent Application Laid-Open No. 2422973 was additionally tested. That is, 1.5 mol of 1-hydroxyethyl-2-heptadecylimidazoline, 1.5 mol of methyl stearate, and 0.1 mol of NaOCH ₃ were placed in a 2 liter 4-neck flask equipped with a stirrer, a thermometer, and a distillation column. Put in. The reaction temperature is heated to 180 ° C. while the reaction flask is evacuated to about 2 mm Hg for 2.5 hours.
No inert gas is allowed to flow in the reaction system. Table 1 shows the evaluation results of the composition, hue, and odor of the obtained reaction product.

Comparative Example 2 An alternative method of synthesizing an ester imidazoline described in Japanese Patent Application Laid-Open No. 2-242973 was repeated. That is, a reflux condenser,
In a 2-liter 4-neck flask equipped with a nitrogen inlet and a stirrer, 1.5 mol of 1-hydroxyethyl-2-heptadecylimidazoline, 1.5 mol of methyl stearate, NaOC
H ₃ are placed together with 0.1 mol. The reaction mixture is heated to 180 ° C. and kept at that temperature for about 2.5 hours. A nitrogen gas is flowed in the reaction system. Table 1 shows the evaluation results of the composition, hue, and odor of the obtained reaction product.

Comparative Example 3 An ester imidazoline synthesis method described in Japanese Patent Application Laid-Open No. 2-1479 was additionally tested. That is, 1.5 mol of 1-hydroxyethyl-2-heptadecyl imidazoline and 1.5 mol of methyl stearate are put together in a 2-liter 4-neck flask equipped with a stirrer, a thermometer and a distillation column. The reaction temperature is heated to 170 ° C. while the reaction flask is evacuated to about 2 mm Hg for 22 hours. No inert gas is allowed to flow in the reaction system. Table 1 shows the evaluation of the composition, hue, and odor of the obtained reaction product.

[0018]

[Table 1]

Note: * 1: iPr indicates an isopropyl group. * 2: The smaller the value, the better the hue. * 3: The odor was evaluated by immediately smelling the synthesized ester imidazoline, and when no odor or slight odor was felt, it was judged as ○, and when a specific odor was felt, it was judged as ×.

[0020]

According to the present invention, ester imidazolines having good hue and odor can be produced in high yield and high purity.

Claims (4)

(57) [Claims] [Claim 1] General formula (1) (Wherein, R ¹ represents a linear or branched 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 linear or branched alkyl group or alkenyl group having 7 to 21 carbon atoms, and R ⁴ is an alkyl group or hydroxy group having 1 to 5 carbon atoms) A fatty acid ester represented by the general formula (3), characterized by reacting with a fatty acid ester represented by the formula (3) in the presence of an esterification catalyst while introducing an inert gas into the reaction system. ) (Wherein, R ¹ , R ² , and R ³ have the same meanings as described above). 2. An imidazoline compound represented by the general formula (1), wherein the inert gas is at least one selected from the group consisting of nitrogen, helium, neon and argon, and is used in the reaction; (2) introducing the inert gas into the reaction system at a rate of 0.01 to 50 liters / hr per 1 kg of the total weight of the fatty acid ester represented by the formula:
A method for producing an imidazoline having an ester group according to claim 1. 3. The method for producing an imidazoline having an ester group according to claim 1, wherein the reduced pressure condition is 5 to 200 mmHg. 4. An esterification catalyst comprising Ti (OR ⁵ ) ₄ , TiX ₄ , Na
OR ⁶ , KOR ⁶ , SnY ₂ , SnY ₄ , SnO and SnOZ (in each formula, R ⁵ is an alkyl group having 1 to 4 carbon atoms, X is a halogen atom, R ⁶ is an alkyl group having 1 to ⁶ carbon atoms, Y Is an alkyl group having 1 to 8 carbon atoms, a hydroxyalkyl group, a halogen atom, a hydroxy group, an inorganic acid residue, an organic acid residue or a fatty acid residue, and Z represents an alkyl group or an aryl group. The method for producing an imidazoline having an ester group according to any one of claims 1 to 3, which is at least one of the following.