JP2780126B2 - Method for producing amidoamine type compound - Google Patents

Description

The present invention relates to an efficient method for producing an amidoamine type compound useful as an amphoteric surfactant.

[Problems to be solved by conventional technology and invention]

In recent years, surfactants used in detergents and the like have been demanded to have high safety, low irritation to eyes and skin, and good biodegradability. One of the surfactants satisfying these needs is an imidazoline-type amphoteric surfactant. Since imidazoline-type amphoteric surfactants have excellent foaming power and detergency, and are extremely low in irritation to eyes and skin, the amount of imidazoline-type amphoteric surfactants used as a major component or additive in recent years, such as a hypoallergenic shampoo, has been reduced. Is growing.

The imidazoline-type surfactant has long been considered to have an imidazoline skeleton, but recent studies have shown that the tertiary amide-type compound represented by the general formula (I) in which the imidazoline ring is cleaved and the general formula (II) It was found to be a mixture of the secondary amide type compounds represented.

[Wherein, R represents a linear or branched alkyl, alkenyl, hydroxyalkyl or aralkyl group having 7 to 23 carbon atoms, and M represents a hydrogen atom, an alkali metal atom, an ammonium group or a cation residue of an alkanolamine. Shown] Such a surfactant is still referred to as an imidazoline-type surfactant from an old custom today, but is herein referred to as an "amidoamine-type surfactant" based on a correct structural formula.

The tertiary amide type compound (I) is characterized in that it has a low viscosity and is easy to handle and has low irritation to eyes and skin, and is more useful as a surfactant than the secondary amide type compound (II). is there.

By the way, amidoamine type surfactants are generally 2-
It is prepared by reacting an alkyl (or 2-alkenyl) imidazoline, a ring-opened compound thereof or a mixture thereof with a monohalogenated acetic acid or a salt thereof. It was not possible to control the content of the secondary amide type compound (II) to produce the compound (I) with high selectivity. Also, in JP-A-61-143347, the reaction of 2-alkylimidazoline with a monohalogenated acetate,
The tertiary amide type compound (I) can be selected by adjusting the pH of the reaction solution to a desired value between 7 and 12 and maintaining the pH of the reaction solution near the above-mentioned adjusted value during the reaction. It is reported that it can be obtained.

However, the present inventors have further tried the present invention, and the high-performance liquid chromatography (hereinafter referred to as HP
As a result of detailed composition analysis using LC)
The product was a mixture of the tertiary amide type compound (I) and the secondary amide type compound (II), and the ratio was about 50/50 by HPLC area ratio. Furthermore, this method requires that the pH of the reaction solution be controlled within a certain range during the reaction,
The operation was complicated for industrial implementation.

Therefore, it has been desired to develop a method for selectively producing a tertiary amide compound (I) useful as a surfactant by a simple operation that can be applied industrially.

[Means for solving the problem]

Under these circumstances, the present inventors have conducted intensive studies and found that a tertiary amide-type compound can be selectively obtained by reacting imidazoline with a monohalogenated acetic acid in the presence of a specific inorganic salt. Thus, the present invention has been completed.

 The present invention is represented by the following reaction formula.

[Wherein X represents a halogen atom, Z represents an alkali metal atom, and R and M have the same meanings as described above] That is, the present invention relates to a compound represented by the formula ZHSO ₃ , Z ₂ S ₂ O ₃ or ZPH ₂ O ₂ Wherein, in the presence of an inorganic salt represented by the formula (wherein Z represents an alkali metal atom) (hereinafter simply referred to as “inorganic salt”), imidazoline (III) is reacted with a monohalogenated acetic acid or a salt thereof. To produce an amidoamine type compound (I).

Examples of the imidazoline (III) as one of the raw materials include 1-hydroxyethyl-2-cocoylimidazoline, 1-hydroxyethyl-2-undecylimidazoline, 1-hydroxyethyl-2-heptadecylimidazoline and the like. it can. Examples of the monohalogenated acetic acid (IV) or a salt thereof include monochloroacetic acid, monobromoacetic acid, and sodium, potassium, ammonium, and alkanolamine salts thereof.

As a specific example of the inorganic salt used in the present invention, NaHS
O ₃ , Na ₂ S ₂ O ₅ , NaPH ₂ O ₂ , KHSO ₃ , K ₂ S ₂ O ₅ , KPH ₂ O _{2 and the} like can be mentioned. These inorganic salts may be used alone or in combination of two or more. The amount of the inorganic salt to be added is preferably at least 300 ppm, particularly preferably at least 500 ppm, based on the total charged amount. 300p
If it is less than pm, a sufficient effect of addition cannot be obtained, while if it is too large, there is no problem in the reaction, but it is disadvantageous in terms of cost, which is not preferable. Therefore, a particularly preferable addition amount is about 500 to 5,000 ppm. These inorganic salts need to be present both during the ring-opening reaction of imidazoline and during the reaction of monohalogenated acetic acid with imidazoline. Therefore, it is preferable to add the inorganic salt to the reaction system from the beginning. Even if the inorganic salt is added during the ring-opening reaction of imidazoline, no sufficient effect is obtained, and no effect can be expected even if added after the reaction.

In the present invention, in order to accelerate the cleavage reaction of the imidazoline ring, it is preferable to add an alkali such as sodium hydroxide, potassium hydroxide and sodium carbonate.

A preferred reaction procedure of the method of the present invention is, for example, as follows. First, imidazoline (III), a minimum amount of an aqueous alkali solution and an inorganic salt required for opening the imidazoline ring are added, and the temperature is raised. After reacting at a temperature of 80 to 90 ° C. for about 1 hour, at least 2 mol, preferably 2 to 3 mol of a previously prepared aqueous monochloroacetate solution is charged, and the reaction is carried out with stirring at 50 to 100 ° C., preferably 60 to 80 ° C. Then, an appropriate amount of an aqueous alkali solution is added dropwise so that the reaction is completed. If the reaction temperature is 40 ° C. or lower, the starting material imidazoline (III) is hardly dissolved, and the amphoteric reaction rate becomes slow. On the other hand, if the temperature is higher than 100 ° C., the coloring and decomposition of the product become intense, which is not preferable.

This reaction may be carried out using only water, but there is no problem even if a solvent such as alcohol is added according to the purpose.

According to the above-mentioned reaction, the tertiary amide type amidoamine compound (I) is present as a main product in the reaction solution, so that it can be isolated. However, when it is used as a surfactant, the compound can be separated from the reaction solution. The reaction solution can be directly incorporated into a detergent composition or the like without isolating (I) at all. The amidoamine compound (I) is usually produced as an alkali metal salt. However, if necessary, the alkali metal may be exchanged for a hydrogen atom, an ammonium group, or a cation residue of an alkanolamine before use.

〔Example〕

Next, the present invention will be described with reference to examples, but the present invention is not limited thereto.

Reference example 1 equipped with a stirrer, thermometer, reflux condenser, and pressure gauge
In a four-necked flask, 200 g (1 mol) of lauric acid and 135.2 g (1.3 mol, hereinafter, AEEA) of aminoethylethanolamine
And abbreviation). The mixture was stirred and heated to 140 ° C. while passing hot water at 80 ° C. through a reflux condenser. Thereafter, the reaction pressure was set at 400 mmHg over 1 hour, and the reaction was carried out for 2 hours to effect amidation.

Next, the reaction temperature was set to 200 ° C. and the pressure was set to 200 mmHg over 1.5 hours, and aging was performed under these conditions for 1 hour. The pressure was further reduced to 10 mmHg over about 2 hours, and the reaction was performed under these conditions for 2 hours to remove excess AEAA. During this time, the generated water and
AEEA vapor was collected in a dry ice / methanol cooled trap. Thus, 1-hydroxyethyl-2-
Undecyl imidazoline was obtained. All the following examples used what was obtained and manufactured by this method.

Example 1 In a four-necked flask equipped with a stirrer, a condenser, a dropping funnel, and a thermometer, 268 g (1 mol) of 1-hydroxyethyl-2-undecylimidazoline obtained in the above Reference Example and 90 g of water were added.
Then, 2 g of sodium hydroxide and ₃ g of NaHSO ₃ were added, the mixture was heated to 80 ° C. while stirring, and stirring was continued at the same temperature for about 2 hours to open the imidazoline ring.

Here, 233 g of sodium monochloroacetate prepared separately
(2 moles) and 662 g of water. Next, while maintaining the temperature of the solution at 70 to 80 ° C., 200 g of 40% sodium hydroxide was added dropwise over about 3 hours. After completion of the dropwise addition, aging was performed at a temperature of 70 to 80 ° C. for 4 hours. Subsequently, heating was stopped and the reaction mixture was cooled. The compound thus obtained was analyzed in detail by HPLC. As a result, the tertiary amide type N
-Lauroyl-N- (2-hydroxyethyl) -N ',
N'-bis (sodium carboxymethyl) ethylenediamine and secondary amide type N-lauroyl-N'-
The area ratio of (2-hydroxyethyl) -N'-sodium carboxymethylethylenediamine by HPLC was 90/10. Further, when the viscosity was measured (at 25 ° C.) with a B-type viscometer, it was about 50 cp.

Example 2 In place of NaHSO ₃ of Example 1, ₃ g of Na ₂ S ₂ O ₅ was used. 3
The ratio of the secondary amide type compound to the secondary amide type compound was 93/7. The viscosity was about 40 cp.

Example 3 In place of NaHSO ₃ of Example 1, ₃ g of NaPH ₂ O ₂ was used. 3
The ratio of the secondary amide type compound to the secondary amide type compound was 85/15. The viscosity was about 60 cp.

Comparative Example 1 The reaction was carried out under the same conditions without adding NaHSO ₃ of Example 1. The ratio of tertiary amide type compound / secondary amide type compound is 5 /
95. The viscosity was about 100,000 cp.

Comparative Example 2 The reaction was carried out as follows according to the method of JP-A-61-143347.

233 g (2 mol) of sodium monochloroacetate, 662 g of water and 268 g (1 mol) of 1-hydroxyethyl-2-undecylimidazoline were charged into the reaction vessel used in Example 1, and the temperature was raised to 70 ° C. while stirring. And add 40
While maintaining the temperature for about 4 hours, 200 g of sodium hydroxide was added dropwise so that the pH was maintained at 7 to 12. After completion of the dropping, aging was performed at the same temperature for about 1 hour. When the compound thus obtained was analyzed, the area ratio of the tertiary amide type compound / the secondary amide type compound by HPLC was 50/50. The viscosity was about 500 cp.

〔The invention's effect〕

According to the present invention, a tertiary amide-type amidoamine compound useful as a surfactant having low viscosity and low skin irritation, which has been extremely difficult to produce conventionally, can be selectively produced at a low cost with a simple operation. It became so.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI C07C 235/10 C07C 235/10 // C11D 1/88 C11D 1/88

Claims (1)

(57) [Claims] (1) In the presence of an inorganic salt represented by the formula ZHSO ₃ , Z ₂ S ₂ O ₅ or ZPH ₂ O ₂ (wherein Z represents an alkali metal atom), a compound represented by the general formula (III): [Wherein R represents a linear or branched alkyl, alkenyl, hydroxyalkyl or aralkyl group having 7 to 23 carbon atoms] to the imidazoline represented by the following general formula (IV) X-CH ₂ COOH (IV) Wherein X represents a halogen atom, wherein a monohalogenated acetic acid or a salt thereof represented by the following general formula (I) is reacted: [Wherein, R represents the same meaning as described above, and M represents a hydrogen atom, an alkali metal atom, an ammonium group, or a cation residue of an alkanolamine].