JP2001097942A - Method for preparing monoglyceride sulfate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for preparing a monoglyceride sulfate, scarcely forming by-products, such as inorganic salts including sodium sulfate, capable of conducting reaction without using solvents, having few restrictions on reactor, and therefore capable of preparing the product at a low cost. SOLUTION: This method for preparing the monoglyceride sulfate comprises reacting an acetal compound of monoglyceride or a ketal compound thereof expressed by general formula (1) (R1 is a residue formed by removing carboxy group from a 6-22C saturated or unsaturated fatty acid; R2 and R3 are each H, a 1-8C straight-chain alkyl, a 1-8C branched-chain alkyl or the like; X is H or-SO3M; and M is a cation) with a sulfating agent to form the monoglyceride sulfate compound of general formula (2).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing monoglyceride sulfate useful as a cleaning base.

[0002]

2. Description of the Related Art Monoglyceride sulfate has a fatty acid and glycerin skeleton in its molecular structure, and is useful as a cleaning base having low irritation and excellent biodegradability. As a method for producing monoglyceride sulfate, trisulfate of glycerin is synthesized from glycerin and 3 times the molar amount of chlorosulfonic acid, and then a hardened fat is added, followed by extraction with water / butanol.
Finally, a method of neutralization (JP-A-1-104699) and a method of sulfating fats and oils and twice the amount of glycerin with excess sulfur trioxide (JP-A-6-503074 and JP-A-6-50307)
5), a method in which pure monoglyceride in coconut composition is reacted with sulfur trioxide, and after neutralization, excess Na ₂ SO ₄ is removed by filtration through a membrane membrane (1996, CESIO Proceedings, A. BEHLER). I have.

However, any of the above methods requires an excess of the sulphating agent in excess of the stoichiometric amount, produces a large amount of inorganic salts, and undergoes hydrolysis due to transesterification under acidic conditions to cause glycerin, diglyceride, triglyceride. And the purification process such as solvent extraction and membrane filtration is indispensable, and the yield of the target product is low, so that the production cost cannot be avoided.

[0004] An object of the present invention is to provide an inexpensive method for producing monoglyceride sulfate, which can be produced without a solvent and has almost no by-products of inorganic salts such as sodium sulfate and can be produced with little restrictions on equipment. .

[0005]

According to the present invention, there is provided a compound represented by the general formula (1):

[0006]

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(Wherein, R ¹ is a residue obtained by removing a carboxyl group from a saturated or unsaturated fatty acid having 6 to 22 carbon atoms, R ² and R ³ are the same or different and each represent a hydrogen atom, a C ^{1 to} C 8 A straight chain or branched chain alkyl group or a group in which R ² and R ³ are linked to form a ring; an acetal or ketal of a monoglyceride (hereinafter referred to as compound (1))
A monoglyceride sulfate represented by the general formula (2), wherein the monoglyceride sulfate is reacted with a sulfating agent and, if necessary, neutralized with a base component.

[0008]

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(Wherein, R ¹ has the same meaning as described above;
Represents a hydrogen atom or -SO ₃ M, M is an alkali metal,
A cation such as an alkaline earth metal, ammonium, mono, di, tri or tetraalkyl ammonium, or mono, di, tri or tetra alkanol ammonium. )

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The compound (1) as a raw material for production of the present invention can be obtained by the following two methods.

<Method 1> Glycerin and general formula (3)

[0012]

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(Wherein R ² and R ³ have the same meanings as described above) (hereinafter referred to as compound (3))
From general formula (4)

[0014]

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After obtaining a dioxolane compound (hereinafter referred to as compound (4)) represented by the formula (wherein R ² and R ³ have the above-mentioned meanings), R ¹ COOR ⁴ (5) (Wherein, R ¹ represents the above-mentioned meaning, R ⁴ represents a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or a residue obtained by removing an R ¹ COO group from fat or oil.) A method of esterifying with the lower alkyl ester or fat (hereinafter referred to as compound (5)).

<Method 2> A method in which glycerin, compound (3) and compound (5) are mixed and reacted. In this case, the mixing is preferably performed simultaneously.

As the compound (3) used herein, acetone, methyl ethyl ketone, methyl propyl ketone,
Examples thereof include ketones such as methyl butyl ketone, diethyl ketone, and cyclohexyl ketone, and aldehydes such as formaldehyde, acetaldehyde, propionaldehyde, and butyl aldehyde, and methyl ethyl ketone is preferable.

The compound (5) may have 6 to 22 carbon atoms.
And lower alkyl esters or fats and oils having a fatty acid residue having 6 to 22 carbon atoms. Specific examples thereof include caproic acid, caprylic acid, 2-ethylhexanoic acid, pelargonic acid, capric acid, undecylenic acid, and lauric acid. Fatty acids such as acid, myristic acid, palmitic acid, stearic acid, arachiic acid, behenic acid, palmitooleic acid, oleic acid, linoleic acid, linolenic acid, isopalmitic acid, isostearic acid, or methyl and ethyl of these fatty acids And non-hardened or hardened oils such as coconut oil, palm oil, palm kernel oil and tallow, and lauric acid, coconut oil and palm kernel oil are preferred.

In the method 1, the reaction between glycerin and the compound (3) is carried out, for example, in the presence of 0.5 to 2 mol% of an acid catalyst such as p-toluenesulfonic acid, in an amount of 1.2 to 1.5 times the molar amount of glycerin. Compound (3), and a hydrocarbon solvent such as hexane, heptane, and toluene are used in an amount of 0.3 to 1.0 times by weight based on the compound (3), and a Dien-Stark dehydration tube and a cooling tube are used. The reaction can be carried out by releasing the generated water out of the system while azeotropically evaporating with the solvent.

The esterification reaction between the compound (4) and the compound (5) is carried out in an amount of 0.1 to 2% by weight based on the whole raw materials.
The reaction is carried out in the presence of a base catalyst such as sodium methylate, preferably at 80 to 200 ° C, more preferably at 120 to 180 ° C, while removing alcohol or water, to obtain compound (1). If necessary, removal operations such as neutralization of the catalyst, adsorption treatment, and filtration are performed, and then purification such as distillation under reduced pressure is performed.

The method 2 is a method for obtaining the compound (1) in one step. In this case, in the presence of an acid catalyst such as paratoluenesulfonic acid in an amount of 0.1 to 2% by weight based on the whole charged raw material, preferably 60 to 200 ° C, more preferably 80 to 120 ° C.
The ketal or acetalization reaction and the esterification reaction are simultaneously performed while removing the water generated at ° C. If necessary, neutralization of the catalyst, adsorption treatment, removal operations such as filtration, etc.,
Thereafter, purification such as distillation under reduced pressure is performed.

In the present invention, sulfuric acid, fuming sulfuric acid, hydrogen sulfate (alkali metal salt, alkaline earth metal salt, ammonium salt, mono-, di-, tri- or tetraalkylammonium) may be used as a sulfating agent to react with compound (1). Salts (total carbon number of 1 to 32), mono, di, tri or tetraalkanol ammonium salts (total carbon number of 2 to 32) and the like. Preferred are sulfuric acid, fuming sulfuric acid, potassium hydrogen sulfate and ammonium hydrogen sulfate. It is. The amount of sulfating agent is
In order to suppress the formation of the inorganic sulfate in the neutralized product, the amount is preferably 0.3 to 3.0 mol times, more preferably 0.8 to 1.0 mol times, relative to the compound (1).

If the reaction temperature of the sulfation reaction of the present invention is too low, especially in the absence of a solvent, the system becomes paste-like and thickens. On the other hand, at a high temperature, the liberation of fatty acids is caused by simultaneous transesterification. -20 to 110 ° C. is preferable, and 30 to 90 ° C. is preferable since by-products of diglyceride and triglyceride occur.
C is more preferred. The reaction time varies depending on the reaction temperature and the solvent, but is preferably several hours, more preferably 1 hour.
~ 10 hours.

When hydrogen sulfate is used as the sulfating agent, a solvent is required because the product solidifies. Various solvents can be used as the solvent, from non-polar solvents such as heptane and tetrahydrofuran to polar solvents such as acetonitrile and dimethyl sulfoxide. When sulfuric acid or fuming sulfuric acid is used, the product is a liquid even without solvent, and it is not necessary to use a solvent together.

In the sulfation reaction of the present invention, aldehydes or ketones are generated with the progress of the reaction. If the system is depressurized and distilled off, the equilibrium of the reaction is shifted and the amount of the unreacted compound (1) is reduced. This is preferable because it can reduce The degree of pressure reduction depends on the boiling point when a solvent is used, but is preferably 2.7 to 6.7 kPa when no solvent is used.

In the case of further neutralization, as a base component to be used, an alkali metal or alkaline earth metal hydroxide, carbonate or alkoxide, ammonia, mono, di, trialkylamine or tetraalkylammonium salt (total carbon the number 1 to 32), or mono-, di-, tri-alkanolamine or tetra alkanolammonium salts (total carbon number 2 to 32) and others as mentioned, preferably _{NaOH, KOH, Na 2 CO 3} , ammonia.

The neutralization is usually carried out with an aqueous solution, but when an aqueous solution of a base component is added to the reaction product, hydrolysis of both the fatty acid ester and the sulfate occurs due to a low pH in the early stage of the neutralization. Therefore, it is preferable to add the reactants to the aqueous solution of the base component while cooling with cold water. Further, in the neutralization to a high-concentration aqueous solution of the base component, hydrolysis is also likely to occur simultaneously. Therefore, it is preferable to adjust the concentration of the aqueous solution so that the solid content at the end of the neutralization is 30% by weight or less.

The monoglyceride sulfate obtained by the method of the present invention may be used as it is, or if necessary, may be purified by a method such as recrystallization, electrodialysis, or solvent extraction.

[0029]

EXAMPLES In the examples,% is% by weight unless otherwise specified.

Synthesis Example 1 230.26 g (2.5 mol) of glycerin, methyl ethyl ketone 27
0.43 g (3.75 mol), 109.65 g of heptane and 4.77 g of p-toluenesulfonic acid were charged into a flask and refluxed while stirring at 400 rpm. Nine hours later, the reaction was terminated because a predetermined amount of dehydration was reached. This was repeated five times, and the reaction finished product was mixed. The catalyst was neutralized with 30.71 g of 28% sodium methylate (methanol solution).
Was 9.8. The pressure was raised to 40 to 87 ° C. and the degree of vacuum to 40 to 0.8 kPa. After distilling off heptane and methyl ethyl ketone, distillation at 50 to 85 ° C. was performed at 0.67 kPa to obtain 1579.5 g of glycerin methyl ethyl ketone ketal. Rate 75.8
%, Gas chromatography purity 97.59%).

Next, 1071.75 g of lauric acid methyl ester
(5 moles), 1461.9 g (10 moles) of a glycerin methyl ethyl ketone ketal and 50.67 g of 28% sodium methylate (methanol solution) were charged into a flask, and heated at 180 ° C. for 3 hours while stirring at 500 rpm under a nitrogen flow. . 35.47 g of Kyoword 600S manufactured by Kyowa Chemical Industry Co., Ltd. was added, and an adsorption treatment was performed at 80 ° C. for 1 hour. After cooling to room temperature,
Filtration gave 2178.0 g of reaction. 176-183 ° C,
Distilled at 0.08kPa to give the C ₁₂ methyl ethyl ketone ketal of monoglyceride of 1321.4g (80.5% yield, gas chromatographic purity 98.97%). Its saponification value was 168.1 KOHg / kg, which was in good agreement with the theoretical value of 170.8 KOHg / kg.

Example 1 A flask was charged with 32.85 g (0.1 mol) of the monoglyceride ketal of Synthesis Example 1, 13.62 g (0.1 mol) of potassium hydrogen sulfate and 150 g of dimethyl sulfoxide.
The mixture was reacted for 9 hours at 70 ° C. and 6.7 kPa for 2.5 hours, and sulfated while distilling off methyl ethyl ketone out of the system. The high-performance liquid chromatography composition of the reaction product was 38.9% monoglyceride, 54.5% monoglyceride monosulfate, and 2.2% unreacted monoglyceride ketal.

This was completely neutralized with a 48% KOH aqueous solution, filtered, concentrated, and recrystallized with 100 g of ethanol. After suction filtration and drying under reduced pressure, 4.8 g of crystals were obtained. This was further recrystallized from deionized water (25 g) under ice-cooling, filtered by suction and dried under reduced pressure to obtain 1.0 g of monoglyceride monosulfate (yield 2.5%, high-performance liquid chromatography purity 97.25).
%). Infrared absorption absorption fatty acid esters to 1730 cm ^-1 in the spectrum, the absorption of hydroxyl groups was confirmed in 3400 cm ^-1. In ¹³ C-NMR, the chemical shift of glycerin carbon is
71.7 ppm for CH ₂ with sulfate ester, 70.2 pp for CH
m, CH ₂ equipped with a fatty acid ester is 67.5Ppm, almost consistent with α- monoglyceride ¹³ C-NMR chemical shifts of glycerol carbon in the monosulfate described in page 10 of JP-A 6-306041 JP.

Example 2 A flask was charged with 32.85 g (0.1 mol) of the monoglyceride ketal of Synthesis Example 1, 11.51 g (0.1 mol) of ammonium hydrogen sulfate and 150 g of dimethyl sulfoxide.
The reaction was performed at 6.7 kPa for 9.5 hours. Table 1 shows the composition of the reaction completed product by high performance liquid chromatography.

Example 3 A flask was charged with 131.4 g (0.4 mol) of the monoglyceride ketal of Synthesis Example 1, and 40.45 g (0.4 mol) of concentrated sulfuric acid was added to 3 parts of the flask.
The solution was added dropwise at 0.degree. 30 ℃, 2.7k
After aging for 2.9 hours at Pa, the acid value was measured and the equivalent of 48% KO
The finished product was added to 334.9 g of an H aqueous solution and deionized water while cooling with ice. Table 1 shows the composition of the obtained monoglyceride sulfate K salt by high performance liquid chromatography.

Example 4 131.4 g (0.4 mol) of the monoglyceride ketal of Synthesis Example 1 was charged into a flask and dehydrated at 90 ° C. and 2.7 kPa. After cooling, 36.75 g (0.4 mol) of fuming sulfuric acid (containing 30% as SO ₃ ) was added dropwise at 30 ° C. and 2.7 kPa over 4 hours. 30 ℃,
After aging for 1 hour at 2.7 kPa, the acid value was measured, and the equivalent of 48% KOH
The finished product was added to an aqueous solution and 600 g of deionized water under ice cooling. Table 1 shows the composition of the obtained monoglyceride sulfate K salt by high performance liquid chromatography.

Example 5 32.85 g of the monoglyceride ketal obtained in Synthesis Example 1
(0.1 mol) and 32.85 g of heptane were charged into a flask, and 30
At room temperature and normal pressure, 10.11 g (0.1 mol) of concentrated sulfuric acid was added dropwise over 5 hours. Thereafter, the mixture was aged at 30 ° C. and normal pressure for 2 hours, and the solvent was removed at 30 ° C. using a rotary evaporator. The acid value of this was measured, and an equivalent amount of a 48% KOH aqueous solution and deionized water 83.7
The solvent was added to g under ice-cooling. Table 1 shows the composition of the obtained monoglyceride sulfate K salt by high performance liquid chromatography.

Example 6 32.85 g of the monoglyceride ketal obtained in Synthesis Example 1
(0.1 mol) and 32.85 g of dimethyl sulfoxide were charged into a flask, and 10.11 g (0.1 mol) of concentrated sulfuric acid was added at 30 ° C. and normal pressure.
Dropped over time. Thereafter, the reaction was carried out at 70 ° C. and 6.7 kPa for 3.5 hours. The acid value of this product was measured and the equivalent of 48% K
The finished product was added to an aqueous OH solution and 50.9 g of deionized water under ice cooling to obtain a monoglyceride sulfate K salt. Table 1 shows the composition of high performance liquid chromatography.

[0039] Comparative Example 1 C ₁₂ monoglyceride (manufactured by Taiyo Kagaku Co., Ltd. Sunsoft 750) 2
7.44 g (0.1 mol) was charged into a flask, and 10.11 g (0.1 mol) of concentrated sulfuric acid was added dropwise at 50 ° C. and 6.7 kPa over 1 hour. After aging for 2 hours at 50 ° C. and 6.7 kPa, as is clear from the composition shown in Table 1, the fatty acid ester was decomposed, and two phases were separated on standing.

[0040]

[Table 1]

[0041]

According to the production method of the present invention, a monoglyceride sulfate having a small amount of inorganic salts can be produced by using a sulfating agent which is relatively easy to handle and does not necessarily require a solvent. Moreover, if the ketone or aldehyde produced at the same time is recovered and reused, the production can be performed at lower cost.

Claims (5)

[Claims] 1. A compound of the general formula (1) (Wherein, R ¹ is a residue obtained by removing a carboxyl group from a saturated or unsaturated fatty acid having 6 to 22 carbon atoms, R ² and R ³ are the same or different and are a hydrogen atom, a straight chain having 1 to 8 carbon atoms or A monoglyceride acetal or ketal (hereinafter referred to as compound (1)) represented by a branched alkyl group or a group in which R ² and R ³ are linked to form a ring; A method for producing a monoglyceride sulfate represented by the general formula (2). Embedded image (In the formula, R ¹ has the same meaning as described above, X represents a hydrogen atom or —SO ₃ M, and M represents a cation.) 2. A method for producing monoglyceride sulfate represented by the general formula (2), wherein the compound (1) is reacted with a sulfating agent and then neutralized with a base component. 3. The process according to claim 1, wherein the pressure in the reaction system is reduced when reacting the compound (1) with the sulfating agent. 4. A compound (1) comprising glycerin and a compound represented by the following general formula (3): (Wherein, R ² and R ³ have the same meanings as described above) from the ketones represented by the general formula (4). (In the formula, R ² and R ³ have the above-mentioned meanings.) After obtaining a dioxolane compound represented by the general formula (5), R ¹ COOR ⁴ (5) (wherein, R ¹ has the above-mentioned meanings) And R ⁴ represents a hydrogen atom, an alkyl group having 1 to 3 carbon atoms or a residue obtained by removing the R ¹ COO group from an oil or fat.), And esterifying with a lower alkyl ester or an oil or fat thereof. The production method according to any one of claims 1 to 3, which is obtained by: 5. A compound (1) comprising a mixture of glycerin, a ketone represented by the general formula (3) and a fatty acid represented by the general formula (5), a lower alkyl ester thereof or a fat or oil, and reacted. The method according to any one of claims 1 to 3, which is obtained.