JP2000095750A - Method for producing α-sulfofatty acid alkyl ester salt with improved odor - Google Patents

Abstract

(57) Abstract: Provided is a method for producing an α-sulfofatty acid alkyl ester salt which can improve the odor of the α-sulfofatty acid alkyl ester salt itself by a simple treatment. SOLUTION: A slurry of α-sulfofatty acid alkyl ester salt is prepared, and the slurry is heated to a temperature of 100 to 15 ° C.
After adjusting to 0 ° C. and a pressure of 1.5 to 11 kg / cm ² , the odor is removed by flashing under reduced pressure or normal pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing an alkyl ester of α-sulfofatty acid, and relates to a method for producing α-sulfofatty acid alkyl ester by a simple method.
-It can improve the odor of the sulfo fatty acid alkyl ester salt.

[0002]

2. Description of the Related Art Alpha-sulfofatty acid alkyl ester salts are used as surfactants, and are particularly highly evaluated for their performance as detergent materials because of their high detergency, good biodegradability and little impact on the environment. ing. Since α-sulfofatty acid alkyl ester salts usually have an odor when used alone, detergent compositions containing α-sulfofatty acid alkyl ester salts include, for example, α-sulfofatty acid alkyl ester salts by masking perfume. Odor improving compositions have been applied. In addition, JP-A-08-0
No. 81694 discloses that the odor of an α-sulfofatty acid alkyl ester salt can be improved by using a fatty acid alkyl ester having an iodine value of 2 or less and a carotenoid content of 10 ppm or less as a raw material. JP-A-07-197080 discloses that odor can be improved by adding zeolite to a detergent composition.

[0003]

However, when the odor is improved by devising the composition of the cleaning composition as described above, there is a problem that the composition of the cleaning composition is limited. When the odor is improved by using a fatty acid alkyl ester having an iodine value of 2 or less and a carotenoid content of 10 ppm or less, distillation,
A process such as hydrogenation, solvent extraction, or centrifugation is required, and there has been a problem that the production process is complicated. Therefore, an object of the present invention is to provide a method for producing an α-sulfofatty acid alkyl ester salt which can improve the odor of the α-sulfofatty acid alkyl ester salt itself. Still another object of the present invention is to provide a method for producing an α-sulfofatty acid alkyl ester salt which can improve the odor of the α-sulfofatty acid alkyl ester salt by a treatment as simple as possible.

[0004]

In order to solve the above-mentioned problems, according to the present invention, a slurry of an α-sulfofatty acid alkyl ester salt is prepared, and the slurry is heated at a temperature of 10 ° C.
An α-sulfofatty acid having an improved odor, which is adjusted to 0 to 150 ° C. and a pressure of 1.5 to 11 kg / cm ² , introduced into a flash can, and flashed under reduced pressure or normal pressure to remove odor. A method for producing an alkyl ester salt is proposed.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The production method of the present invention is to obtain, for example, an α-sulfofatty acid alkyl ester salt by sequentially performing the following steps (A) to (E). (A) a sulfonating gas introducing step of bringing a fatty acid alkyl ester into contact with a sulfonating gas. (B) Aging step. (C) an esterification step of esterification with a lower alcohol. (D) a neutralization step of obtaining a slurry of α-sulfofatty acid alkyl ester salt from α-sulfofatty acid alkyl ester by neutralization with an alkali. (E) An odor removing step of flushing the slurry of the α-sulfofatty acid alkyl ester salt to remove odor.

The above steps (A) to (C) are steps for producing an α-sulfofatty acid alkyl ester from a fatty acid alkyl ester. That is, regarding the sulfonation mechanism of fatty acid alkyl ester, Smith and Stirto
n: JAOCS vol. 44, p. 405 (1967) and
Schmid, Baumann, Stein, Dolhaine: Proceeding of
the World Surfactants Congress Munchen, vol.
2, p. 105, Gelnhausen, Kurle (1984) and H. Yoshimura: Oil Chemistry (JJOCS), 41, 10 (1
992), the reaction proceeds according to the following reaction scheme.

[0007]

Embedded image

As shown in this reaction scheme,
When a fatty acid alkyl ester is sulfonated, a reaction in which SO ₃ is inserted into an alkoxy group occurs first, and a single molecule SO ₃ adduct is produced. Then, in the next stage, it is further introduced sulfonic group into position by reaction with SO ₃ alpha, SO ₃ bimolecular adduct is produced. Finally, the SO ₃ inserted into the alkoxy group is eliminated to produce an α-sulfofatty acid alkyl ester.

Since the reaction rate of this reaction is low, as described above, after the fatty acid alkyl ester is brought into contact with a sulfonation gas such as SO ₃ gas (A), the reaction is maintained at a predetermined temperature after the sulfonation gas introduction step. (B) An aging step is provided, and further, in the (C) esterification step, the remaining S
The O ₃ biadduct is esterified with a lower alcohol to promote the elimination of SO ₃ inserted into the alkoxy group to form α-
Sulfo fatty acid alkyl ester.

Preferred examples of the conditions in each of the steps (A) to (E) are shown below. (A) Sulfonated gas introduction step In the present invention, preferably, the following general formula (I): R ¹ CH ₂ COOR ² (I) wherein R ¹ represents an alkyl group having 6 to 24 carbon atoms; R ² represents an alkyl group having 1 to 6 carbon atoms).

Fatty acid alkyl esters include animal fats and oils derived from beef tallow, fish oil, etc .; vegetable fats and oils derived from coconut oil, palm oil, soybean oil, etc .; synthesis derived from the oxo process of α-olefin. Any of fatty acid alkyl esters may be used, and there is no particular limitation. In particular,
Methyl or ethyl laurate; methyl or ethyl palmitate; methyl or ethyl stearate; methyl or ethyl hardened tallow fatty acid; methyl or ethyl fatty acid fish oil; methyl or ethyl coco fatty acid; methyl or ethyl palm oil fatty acid; Palm kernel oil fatty acid methyl or ethyl can be exemplified, and these can be used alone or in combination of two or more. In addition, since the odor is weaker as the iodine value is lower, it is preferable to use those having an iodine value of 1.0 or less.

Examples of the sulfonated gas include SO ₃ gas, fuming sulfuric acid and the like, and preferably, SO ₃ gas is used. It is common to use SO ₃ gas diluted to a concentration of 3 to 30% by volume with an inert gas such as air or nitrogen.
SO ₃ is 1.0 to 2.
It is used in an amount of 0 times, preferably 1.0 to 1.5 times, more preferably 1.05 to 1.3 times. If it is less than 1.0 mole, the sulfonation reaction does not proceed sufficiently,
If the molar ratio is more than twice, the sulfonation reaction becomes more severe, so that coloring due to local heat is likely to occur, which is inconvenient.

The reaction system is not particularly limited, and a system such as a tank type reaction, a film reaction, a tube type gas-liquid multi-phase flow reaction and the like are applied. The sulfonation method is not particularly limited, and a thin film type sulfonation method, a batch type sulfonation method and the like are applied. When importance is placed on the color tone of the α-sulfo fatty acid alkyl ester, a batch-type sulfonation method is desirable, but when importance is attached to the cost at the production level, a thin-film sulfonation method is desirable. The reaction temperature is a temperature at which the fatty acid alkyl ester has fluidity. Generally, it is higher than the melting point of the fatty acid alkyl ester, preferably from the melting point to a temperature 70 ° C. higher than the melting point. The reaction time depends on the sulfonation method,
For example, it takes about 5 to 60 seconds for the thin film type sulfonation method and about 10 to 120 minutes for the batch type sulfonation method.

(B) Aging step The temperature of the aging step is suitably from 70 to 100 ° C. 70 ° C
If the temperature is lower than this, the reaction does not proceed quickly, and if the temperature is higher than 100 ° C., the color may be easily formed. Reaction time is 1 to 120
Minutes.

It is preferable that at least the aging step (B) is performed in the presence of a coloring inhibitor. As a coloring inhibitor,
Various types proposed by the present applicant can be used. For details of effective coloring inhibitors, refer to Japanese Patent Application No. 08-2.
No. 4433, Japanese Patent Application No. 08-336077, Japanese Patent Application No. 08
-340149, Japanese Patent Application No. 08-340148, Japanese Patent Application No. 08-340147, Japanese Patent Application No. 08-342244.
JP-A-09-216861, JP-A-09-2682
No. 16862, JP-A-09-216863, and the like. Among these, JP-A-09-21
It is preferable to use an inorganic sulfate having a monovalent metal ion and having an average particle size of 250 μm or less, which is disclosed in JP-A-68663. Inorganic sulfate has a high coloring suppression effect, is often inexpensive, and is a component that is added to detergents.
There is no need to remove from sulfo fatty acid alkyl ester salts (products).

The inorganic sulfate is not particularly limited as long as it is a powdery anhydrous salt having a monovalent metal ion, and examples thereof include sodium sulfate, potassium sulfate, and lithium sulfate. The inorganic sulfate having an average particle size of 250 μm or less, preferably 50 μm or less is used. During the reaction, the inorganic sulfate hardly dissolves in the reaction solution to the extent that its surface is slightly dissolved, and is dispersed in the reaction solution. Therefore, by using such an inorganic sulfate having a small particle size, the contact area is large, the dispersibility is improved, and the effect can be further enhanced. The amount of the coloring inhibitor added is 0.1 to 20% by weight, preferably 2 to 10% by weight, based on the fatty acid alkyl ester as the raw material. If it is less than 0.1% by weight, the effect of addition cannot be obtained.

The inorganic sulfate (coloring inhibitor) may be present at least in the aging step (B). Therefore, in order to simplify the operation, it is customary to add the inorganic sulfate to the fatty acid alkyl ester and to subject the mixture to the (A) sulfonation gas introduction step. An inorganic sulfate may be added between the step (B) and the aging step.

(C) Esterification Step The lower alcohol used in the esterification step preferably has 1 to 6 carbon atoms, which is equal to the number of carbon atoms in the alcohol residue of the starting fatty acid alkyl ester, but is not particularly limited. There is no. The lower alcohol is 0.5 to 5.0 moles, preferably 0.8 to 2.0 moles per mole of the bimolecular adduct in the reaction solution.
It is used in a molar amount of 0 times. The reaction temperature is 50 to 100 ° C, preferably 50 to 90 ° C, and the reaction time is 5 to 120 minutes.

(D) Neutralization Step The neutralization step is preferably performed when the pH of the neutralized solution of the α-sulfofatty acid alkyl ester and the alkali is in the acidic or weakly alkaline range (pH 4 to 9). In the case of strong alkali, the ester bond may be easily broken. As the alkali, for example, an aqueous solution of an alkali metal, an alkaline earth metal, ammonia, and ethanolamine is used. The concentration of the alkaline aqueous solution is about 2 to 40% by weight. Neutralization temperature is 30-70 ° C, neutralization time is 10-6
0 minutes. The concentration of the activator (concentration of active ingredient (AI concentration)) in the neutralized liquid (slurry) is 60 to 80% by weight,
Preferably, it is 65 to 75% by weight. The activator concentration is the total concentration of the α-sulfofatty acid alkyl ester salt and the by-product α-sulfofatty acid dialkali salt. When the viscosity is out of this range, the viscosity of the slurry is significantly increased, or in the range where the viscosity of the slurry is low, the concentration of the activator is significantly lowered. If the viscosity of the slurry is high, handling such as pumping becomes difficult, and it may not be possible to introduce the slurry into the flash can in the (E) odor removing step. If the concentration of the activator is low, the production efficiency is disadvantageously reduced.

If necessary, before or after the (D) neutralization step, a treatment for improving the color tone of the α-sulfofatty acid alkyl ester salt to a color close to white can be performed. The treatment for improving color tone includes, for example, a bleaching treatment using a bleaching agent such as hydrogen peroxide, and is preferably performed after the (D) neutralization step.

(E) Odor removal step (D) The slurry of the α-sulfofatty acid alkyl ester salt obtained in the neutralization step is adjusted to a temperature of 100 to 150 ° C. and a pressure of 1.5 to 11 kg / cm ² and then flashed. It is introduced into a can and flushed under reduced pressure or normal pressure to remove odor.

That is, at least the slurry of the α-sulfofatty acid alkyl ester salt in the container or the pipe just before the introduction of the flash can is heated and pressurized as needed to a temperature of 10 ° C.
The pressure is adjusted to 0 to 150 ° C. and the pressure is adjusted to 1.5 to 11 kg / cm ² , then introduced into a flash can and flashed under reduced pressure or normal pressure to selectively evaporate the low-boiling components causing odor. To improve the odor of the α-sulfofatty acid alkyl ester salt. The shape of the flash can, the flash method, the flash nozzle and the like are not particularly limited. The flash can be recycled or performed continuously in multiple stages. Specifically, the activator concentration of the slurry after the flush is set so as to maintain the range of 60 to 80% by weight, preferably 65 to 75% by weight, similarly to the activator concentration before the flush. If this range cannot be maintained, the viscosity of the slurry increases as described above, making handling difficult. Preferably, the unit weight of the active agent (active ingredient) (1
When the evaporation amount per kg) is set to about 10 to 200 g, the odor can be more reliably improved. If the temperature of the slurry before the introduction of the flash can exceeds 150 ° C. or the pressure exceeds 11 kg / cm ² , the amount of evaporation becomes too large to maintain the preferable range of the activator concentration, or the heat of the activator cannot be maintained. Deterioration may occur. Temperature less than 100 ° C or pressure 1.5kg / cm
^When it is less than ² , the effect of improving odor is insufficient. Further, the temperature, pressure, residence time in the flash can, and the like of the flash can are appropriately adjusted depending on the volume of the flash can, the processing volume of the slurry, and the like. Usually, the pressure in the case of reduced pressure is 150 to 600 mmHg, and the residence time is It is about 1 to 120 minutes.

After the (E) odor removing step, the α-sulfofatty acid alkyl ester salt is formed into a powder or a particle form from the slurry of the α-sulfofatty acid alkyl ester salt by a conventional method to obtain a product. obtain.

As described above, in the above-described manufacturing method,
In steps (A) to (C), the fatty acid alkyl ester is sulfonated to produce an α-sulfofatty acid alkyl ester, and in the (D) neutralization step, a slurry of the α-sulfofatty acid alkyl ester salt is prepared.
(E) In the odor removing step, the odor of the α-sulfofatty acid alkyl ester salt itself can be improved by a simple operation of introducing it into a flash can. Therefore, the composition of the detergent composition is not limited as in the conventional case, and no troublesome treatment of the fatty acid alkyl ester is required. Further, since the α-sulfofatty acid alkyl ester salt after the step (E) is a slurry adjusted to have a low viscosity, handling such as pumping to the subsequent step is easy. In this production method, α-
The neutralized solution (slurry) generated during the production of the sulfofatty acid alkyl ester salt is subjected to the (E) odor removing step, but is not limited thereto. The α-sulfofatty acid alkyl ester salt in the form of particles can also be used as a slurry again to remove the odor by performing the same operation as in the above (E) odor removal step.

The embodiments of the present invention are summarized as follows. That is, (E) the slurry of the α-sulfofatty acid alkyl ester salt before being subjected to the odor removing step has an activator concentration of 60 to 80% by weight, preferably 65 to 75% by weight. Then, in the flash of the (E) odor removing step, the slurry of the α-sulfofatty acid alkyl ester salt is heated to a temperature of 100 to 150 ° C. and a pressure of 1.5 to 1 ° C.
It is introduced into a flash can at 1 kg / cm ² and flashed under reduced pressure or normal pressure. Specifically, the activator concentration of the slurry after flushing is set so as to maintain the range of 60 to 80% by weight, preferably 65 to 75% by weight. More preferably, the unit weight of the activator (1 kg)
The amount of evaporation per unit is set to be about 10 to 200 g. Usually, the pressure in the flash can is 150 to 600 mmHg and the residence time is about 1 to 120 minutes when the pressure is reduced.

[0026]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. Preparation of Sample 1: Mixed fatty acid methyl ester (iodine value: 0.03) having a weight ratio of methyl myristate and methyl palmitate of 2: 8, anhydrous sodium sulfate as a coloring inhibitor, and mixed fatty acid methyl ester 5 for
% By weight. Then, in a 10 L stainless steel reaction tank equipped with a stirrer and passed through a jacket, 1.2 times mol of sulfuric anhydride gas diluted to 8% by volume with nitrogen gas (relative to mixed fatty acid methyl ester) was contacted at a reaction temperature of 80 ° C. The mixture was further aged for 30 minutes while maintaining the temperature at 80 ° C. Then
4 to the α-sulfofatty acid alkyl ester after aging
The esterification was carried out by adding wt% methanol. Further, neutralization was performed with a 34% by weight aqueous sodium hydroxide solution to prepare a slurry of α-sulfofatty acid methyl ester salt having an activator concentration of about 70% by weight.

(Example 1) To the above-mentioned sample 1, 35% by weight of hydrogen peroxide based on the α-sulfofatty acid methyl ester salt was added in an amount of 1.0% by weight as a pure component, and heated to 80 ° C. 3
Time bleaching was performed to obtain a slurry having an activator concentration of 68.6% by weight. After cooling this slurry, 120 ° C, 4 kg / c
After heating and pressurizing to m ² , the mixture was introduced into a flash can and flushed under normal pressure. After cooling this slurry, the odor was evaluated.

(Comparative Example 1) To the above-mentioned sample 1, 1.0% by weight of pure hydrogen was added to 35% by weight of aqueous hydrogen peroxide based on the α-sulfo fatty acid methyl ester salt. Then, the mixture was heated to 120 ° C., bleached for 60 minutes, and then cooled at room temperature. After cooling was completed, the odor of the slurry having the activator concentration of 68.8% by weight was evaluated.

Preparation of sample 2: 10 L stainless steel with a stirrer in which water was passed through a jacket to a mixed fatty acid methyl ester (iodine value: 0.05) having a weight ratio of methyl palmitate and methyl stearate of 7: 3. In the reaction tank
A 1.2-fold molar amount of sulfuric anhydride gas (to mixed fatty acid methyl ester) diluted to 8% by volume with nitrogen gas was reacted at a reaction temperature of 80 ° C.
And then aged for 30 minutes while maintaining at 80 ° C. Next, 4% by weight of methanol was added to the aged α-sulfofatty acid methyl ester to perform esterification. Further, the slurry was neutralized with a 32% by weight aqueous solution of sodium hydroxide to prepare a slurry of α-sulfofatty acid methyl ester salt having an activator concentration of about 70% by weight.

Example 2 To the above-mentioned sample 2, 2.0% by weight of hydrogen peroxide aqueous solution of 35% by weight with respect to the α-sulfo fatty acid methyl ester salt was added in a pure content. Then 120 ° C
, And bleached for 90 minutes to obtain a slurry having an activator concentration of 67.3% by weight. After cooling this slurry, 130
After heating and pressurizing at 6 ° C. and 6 kg / cm ² , the mixture was introduced into a flash can and flushed under normal pressure. After cooling the obtained slurry, the odor was evaluated.

Comparative Example 2 To the above-mentioned Sample 2, 2.0% by weight of a 35% by weight aqueous hydrogen peroxide solution was added to the α-sulfofatty acid methyl ester salt in pure content. Then 130 ° C
And bleached for 90 minutes, and then cooled at room temperature. After the cooling was completed, the odor of the slurry having the activator concentration of 67.5% by weight was evaluated.

The samples of Examples 1 and 2 and Comparative Examples 1 and 2 were subjected to a sensory evaluation of odor by five panelists immediately after production, and evaluated according to the following criteria. A: Almost odorless. ：: Some smell, but masking of fragrance etc. is possible. Δ: A considerable odor was felt, and masking of fragrances and the like was impossible. X: Strong odor. Further, the samples of Examples 1 and 2 and Comparative Examples 1 and 2 were stored in a constant temperature room at 40 ° C., and those that had passed for one month were evaluated in the same manner as described above. Tables 1 and 3 show the composition, color tone, and reaction rate of the fatty acid methyl ester of the slurry of the α-sulfo fatty acid methyl ester salt. Table 2 shows the odor evaluation results.
The results are shown in Table 4. In Tables 1 and 3,% indicates% by weight,
Al indicates the activator concentration of the slurry, and methyl sulfate, sodium sulfate, and Di-Na (α-sulfofatty acid disodium salt) are by-products. The color tone was determined by adding a 5% by weight ethanol solution of α-sulfofatty acid methyl ester salt to 40 m
m optical path length, No. 42 is a value measured by a Krett photoelectric meter using a blue filter.

[0033]

[Table 1]

[0034]

[Table 2]

[0035]

[Table 3]

[0036]

[Table 4]

From the results in Tables 2 and 4, it can be seen that the odor of the α-sulfofatty acid methyl ester salt is improved by removing the odor introduced into and flushed into the flash can, and this effect is maintained even after long-term storage. Was confirmed.

[0038]

As described above, in the production method of the present invention, the odor of the α-sulfofatty acid alkyl ester salt itself is obtained by a simple operation of introducing the slurry of the α-sulfofatty acid alkyl ester salt into a flash can. Can be improved. Therefore, the composition of the cleaning composition is not limited as in the related art. Also, troublesome treatment of the fatty acid alkyl ester is not required.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masahisa Yoshiya 1-3-7 Honjo, Sumida-ku, Tokyo Inside Lion Corporation (72) Inventor Seiji Matoba 1-3-7, Honjo, Sumida-ku, Tokyo No. Within Lion Corporation (72) Inventor Yozo Miyawaki 1-37 Honjo, Sumida-ku, Tokyo F-term within Lion Corporation 4D077 AB10 BA07 BA13 CA02 CA03 CA04 CA14 CA20 DB07Z DC02Z DC32Z DC62Y 4H006 AA02 AB68 AC61 AD13 BA02 BC10 BC11 BE43 BT12 TB53

Claims (1)

[Claims] 1. A slurry of an α-sulfofatty acid alkyl ester salt is prepared, and the slurry is heated to a temperature of 100 to 15 ° C.
After adjusting to 0 ° C. and a pressure of 1.5 to 11 kg / cm ² , the mixture is introduced into a flash can and flashed under reduced pressure or normal pressure to remove odors. Method for producing salt.