JP3003305B2 - Method for producing α-sulfo fatty acid ester salt - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing an α-sulfofatty acid ester salt (hereinafter abbreviated as “α-SFE”).

[0002]

2. Description of the Related Art α-SFE is a compound known as a surfactant having good detergency, hard water resistance and biodegradability. Conventionally, a higher fatty acid methyl ester or a higher fatty acid ethyl ester is directly sulfonated with sulfuric anhydride. And neutralized. However, if an alcohol component constituting the ester is to produce α-SFE, which is an alcohol having a longer chain or a branched chain, based on the conventional method, steric hindrance or an electronic effect (I effect) may occur. There is a disadvantage that the conversion of sulfonation is very low.

As an alternative method, a method is known in which a fatty acid is first sulfonated with sulfuric anhydride and then esterified with an alcohol having 1 to 4 carbon atoms to neutralize the remaining acid component (JAOCS, 42). , 1078 (1965)). However, this method has disadvantages such as requiring a high reaction temperature since the melting point of the fatty acid as a raw material is higher than that of the higher fatty acid alkyl ester, or requiring a chlorinated solvent such as carbon tetrachloride. Was.

[0004]

SUMMARY OF THE INVENTION The inventors of the present invention have found that α-SFE, which has been difficult to produce in the conventional method, is that the alcohol component constituting the ester is an alcohol having a longer or branched chain. As a result of intensive studies to develop an industrial production method capable of easily producing a certain α-SFE at a high yield, a specific fatty acid lower alkyl ester was applied as a raw material, which was sulfonated according to a conventional method, and then subjected to sulfonation. Α-SFE was found to be obtained in high yield by transesterification using the alcohol of the formula (1), and the present invention was completed based on such findings. That is, an object of the present invention is to provide a novel and useful industrial production method of α-SFE.

[0005]

An α-SFE according to the present invention
Is a method for sulfonating a methyl or ethyl ester of a linear or branched fatty acid having 8 to 22 carbon atoms (hereinafter referred to as "fatty acid lower alkyl ester") with sulfuric anhydride, and then converting the sulfonated product having a carbon number of 3
One or two or more alcohols selected from linear or branched aliphatic alcohols having from 8 to 8 alkylene oxide adducts of linear or branched aliphatic alcohols having 1 to 4 carbon atoms; It is characterized by transesterification and then neutralization.

[0006] Fatty acid lower alkyl esters used as raw materials include, for example, animal fats and oils such as beef tallow, lard, fish oil and the like.
Palm oil, coconut oil, vegetable oils such as palm kernel oil are transesterified with methanol or ethanol by a usual method, or a fatty acid having an alkyl chain and methanol or ethanol are acid-catalyzed or non-catalyzed. Obtained by esterification.

[Sulfonation Step] These lower alkyl esters of fatty acids are brought into contact with sulfuric anhydride diluted with about 5 to 20 times the amount of a dried inert gas (eg, dry air, dry nitrogen gas, etc.). The desired α-sulfofatty acid lower alkyl ester is obtained by introducing a sulfone group at the α-position. At this time, the lower the iodine value of the raw material ester, the better, and specifically, it is desirably 1 or less. This is because, when the ester of the raw material has an unsaturated bond, sulfuric anhydride reacts with the unsaturated bond, and a sulfone group is introduced in addition to the α-position, thereby lowering the yield of the target product. is there.

[0008] The preferred amount of sulfuric anhydride to be applied is usually 1.1 to 1.7 relative to 1 mole of the lower alkyl fatty acid ester.
Mol, more preferably about 1.2 to 1.5 mol.
If the amount is less than 1.1 mol, the yield is significantly reduced, and if it exceeds 1.7 mol, the hue of the obtained sulfonated product is significantly deteriorated.

The sulfonation is carried out under heating at about 60 to 90 ° C., preferably about 70 to 80 ° C., usually for 40 minutes to 2 hours.
Complete in about an hour.

The reaction is carried out by reacting a compound inert to sulfuric anhydride,
For example, a chlorine-based compound such as carbon tetrachloride, 1,2-dichloroethane, or a fluorine-based compound can be used as a solvent. However, it is preferable to carry out the reaction without using a solvent from an industrial, economic, and environmental viewpoint.

After the completion of the reaction, excess sulfuric anhydride in the sulfonated product formed is removed by topping or by passing an inert gas such as air through the product, if necessary, or by using water, methanol or the like. The sulfuric anhydride is deactivated, and if necessary, bleaching is performed using a bleaching agent such as hydrogen peroxide.

[Transesterification Step] To the sulfonated product obtained in the above step, a predetermined amount of an alcohol having a target residue is added, and usually under an atmosphere of an inert gas, the melting temperature of the sulfonated product is not less than For example, about 50 to 150 ° C,
The reaction is carried out preferably at about 70 to 100 ° C. for about 5 minutes to 3 hours, preferably for about 30 minutes to 2 hours. When the temperature is lower than the above-mentioned temperature, the sulfonated material as a raw material is solidified, or the reaction time is prolonged, thereby lowering the productivity. If the time is shorter than 5 minutes, the transesterification is not sufficiently performed, while the reaction for a long time is economically undesirable.

Examples of the raw material alcohols include linear or branched aliphatic having 3 to 8 carbon atoms such as propyl alcohol, isopropyl alcohol, butyl alcohol, isobutyl alcohol, hexanol, octanol and 2-ethylhexanol. Alcohol.
Examples of the alkylene oxide adduct of a linear or branched aliphatic alcohol having 1 to 4 carbon atoms include a compound obtained by adding about 1 to 3 mol of ethylene oxide and / or propylene oxide to an alcohol having the carbon number. Is exemplified. Further, as specific examples of more suitable compounds, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether,
Examples thereof include diethylene glycol monoisobutyl ether, propylene glycol monomethyl ether, and propylene glycol monoethyl ether. These alcohols may be used alone or in an appropriate combination of two or more.

In this reaction, the alcohol is usually
It is used in an amount of about 1 to 7 moles, preferably about 2 to 5 moles, per mole of the sulfonate as a raw material. The use of an excessive amount of alcohols can improve the reactivity, while an excessive amount requires a large-sized apparatus, which is not preferable because it lowers the yield and deteriorates profitability.

The alcohol component derived from the raw material ester such as methanol or ethanol is distilled while passing an inert gas such as air, nitrogen or argon through the system, or continuously adding alcohol under reduced pressure. By removing, the transesterification rate can be increased.

[Neutralization Step] This step is carried out by adding a predetermined alkali to the transesterification reaction product, and usually under heating at normal temperature to about 60 ° C. As the predetermined alkali, sodium hydroxide, potassium hydroxide, calcium hydroxide,
Examples thereof include alkali hydroxides such as magnesium hydroxide and aluminum hydroxide, alkanolamines such as ethanolamine, diethanolamine and triethanolamine, and ammonia.

Further, after neutralization, unreacted alcohol is distilled off if necessary, and if decolorization is required, 60 to 8
The solution is bleached at 0 ° C. using hydrogen peroxide or sodium dichlorite to obtain an aqueous solution of α-SFE having a concentration of about 10 to 40% by weight.

The α-SFE thus obtained has a good hue and excellent stability over time, and can be used for clothing detergents, kitchen detergents,
It is useful as a surfactant component such as various toiletry products such as shampoos and rinses, cosmetic products such as creams, industrial emulsifiers, dispersants, solubilizers, foaming agents, penetrants, and fiber oil agents.

[0019]

The present invention will be described in detail below with reference to examples. In each case, the conversion rate to the target α-SFE was determined by HPLC method [Shampoo analysis method, J. Soc. Cosmet.
m.Japan, 21 (1), 5 (1987)]. The conditions are described below. Apparatus: High performance liquid chromatograph LC-3A (manufactured by Shimadzu) Column: Shimpack CLC-ODS (6φ × 150mm)
(Made by Shimadzu Corporation) Mobile phase: methanol / water = 80/20 (v / v), 0.1
Adjust pH to 2.5 with 25M-sodium perchlorate and phosphoric acid Flow rate: 1.0 ml / min Column temperature: 45 ° C Detector: RID-6A

Example 1 214 g (1 mol) of methyl laurate was placed in a 2 l four-necked flask equipped with a stirrer, thermometer, condenser and gas inlet.
And 10% sulfuric anhydride diluted to 5% with dry air.
4 g (1.3 mol) are blown into the ester at 70 ° C.
Thereafter, aging was performed at 80 ° C. for 1 hour. Then, 60 g (1 mol) of isopropanol was added, and transesterification was performed at 70 ° C. for 20 minutes. Further, 60 g (1 mol) of isopropanol was added dropwise over 20 minutes, and the reaction was completed while distilling off methanol under a slight reduced pressure. Then, after cooling to room temperature, 15
Neutralized with aqueous sodium hydroxide solution. pH 7
After fine adjustment, the mixture was aged at 60 ° C. for 1 hour. Then, excess isopropanol was distilled off under reduced pressure, and a predetermined amount of water was added to obtain 1050 g of a 30% by weight aqueous solution of isopropyl α-sulfollaurate (conversion rate: 92%).

Example 2 284 g of ethyl palmitate was placed in the same reactor as in Example 1.
(1 mol) and sulfonated under the same conditions as in Example 1. Then, 148 g (2 mol) of isobutanol
Was added and transesterified at 90 ° C. for 20 minutes. Furthermore,
148 g (2 mol) of isobutanol was added dropwise over 30 minutes, and the reaction was completed while distilling off ethanol under a slight reduced pressure. Subsequently, neutralization and aging treatment were performed in the same manner as in Example 1. Thereafter, excess isobutanol was distilled off under reduced pressure, and a predetermined amount of water was added to obtain 1260 g of a 30% by weight aqueous solution of isobutyl α-sulfolaurate (91% conversion).

Example 3 298 g of methyl stearate was placed in the same reactor as in Example 1.
(1 mol) and sulfonated under the same conditions as in Example 1. Then, 261 g of 2-ethylhexanol
(2 mol) and transesterified at 90 ° C. for 20 minutes. Furthermore, 261 g (2 mol) of 2-ethylhexanol
Was added dropwise over 40 minutes, and the reaction was completed while distilling off methanol under slightly reduced pressure. Next, neutralization was performed in the same manner as in Example 1.
Aged. Then, using a 3 l four-necked flask,
Excess 2-ethylhexanol was distilled off under reduced pressure, and a predetermined amount of water was added to obtain 2340 g of a 20% by weight aqueous solution of 2-ethylhexyl α-sulfostearate (conversion rate: 9).
4%).

Example 4 In the same reactor as in Example 1, hydrogenated tallow fatty acid ethyl 300 was added.
g (1 mol) was charged and sulfonated under the same conditions as in Example 1. Next, 324 g (2 mol) of diethylene glycol monoisobutyl ether was added,
Transesterification was performed for 0 minutes. Further, 486 g (3 mol) of diethylene glycol monoisobutyl ether was added dropwise over 40 minutes, and the reaction was completed while distilling off ethanol under a slight reduced pressure. Subsequently, neutralization and aging treatment were performed in the same manner as in Example 1. Thereafter, the excess diethylene glycol monoisobutyl ether was distilled off under reduced pressure, and a predetermined amount of water was added to the residue.
1620 g of an aqueous solution of 0% by weight of α-sulfo hydrogenated tallow fatty acid diethylene glycol monoisobutyl ether was obtained (conversion rate: 94%).

Example 5 284 g of ethyl palmitate was placed in the same reactor as in Example 1.
(1 mol) and sulfonated under the same conditions as in Example 1. Next, 90 g (1 mol) of propylene glycol monomethyl ether was added, and transesterification was performed at 80 ° C. for 20 minutes. Further, 270 g (3 mol) of propylene glycol monomethyl ether was added dropwise over 30 minutes, and the reaction was completed while distilling off ethanol under slightly reduced pressure. Subsequently, neutralization and aging treatment were performed in the same manner as in Example 1. afterwards,
Excess propylene glycol monomethyl ether was distilled off under reduced pressure, and a predetermined amount of water was added to obtain 980 g of a 40% by weight aqueous solution of propylene glycol monomethyl ether α-sulfolaurate (91% conversion).

Comparative Example 1 312 g (1 mol) of isobutyl palmitate was directly sulfonated with 104 g (1.3 mol) of sulfuric anhydride under heating at 80 ° C. without solvent. Then, after cooling to room temperature, 15%
And neutralized with an aqueous solution of sodium hydroxide. After fine adjustment to pH 7, the mixture was aged at 60 ° C. for 1 hour. As a result, α
The sulfonation rate of isobutyl sulfopalmitate is 42
% Was low.

[0026]

By applying the method according to the present invention, the desired α-sulfofatty acid ester salt can be produced in good yield under industrially advantageous conditions.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) C07C 303/06 C07C 309/17

Claims (1)

(57) [Claims] 1. A straight-chain or branched-chain fatty acid having 8 to 22 carbon atoms, which is obtained by sulfonating a methyl or ethyl ester of a linear or branched fatty acid having 8 to 22 carbon atoms with sulfuric anhydride. Is transesterified with one or more alcohols selected from alkylene oxide adducts of linear or branched aliphatic alcohols having 1 to 4 carbon atoms, followed by neutralization. A method for producing an α-sulfofatty acid ester salt, which is characterized by the following.