JP2001181271A - Method for producing α-monoglyceride ketal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a simple and efficient method for producing a high-purity α-monoglyceride ketal and a method for producing α-monoglyceride using the same. SOLUTION: An acid (1), a ketone or an aldehyde (2), and a glycerin are reacted in the presence of a catalyst to obtain an α-monoglyceride ketal (3), and the obtained α-monoglyceride ketal is obtained. Deketalization gives α-monoglyceride. R ¹ —COOH (1) R ² —CO—R ³ (2) [R ¹ is a hydrogen atom or an aliphatic hydrocarbon group having 1 to 23 carbon atoms, R ² and R ³ are a hydrogen atom, an alkyl group having 1 to 22 carbon atoms, an aryl group having 6 to 30 carbon atoms, and the like. ]

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to α-α which is widely used as an emulsifier, humectant and industrial emulsifier for cosmetics.
The present invention relates to a method for easily and efficiently producing α-monoglyceride ketal, which is a synthetic intermediate of monoglyceride, with high purity, and a method for producing α-monoglyceride using the same.

[0002]

2. Description of the Related Art As a method for obtaining α-monoglyceride, a mixture of monoglyceride, diglyceride and triglyceride was obtained by directly reacting oil and fat with glycerin in the presence of alkali without passing through α-monoglyceride ketal. Later, a method of obtaining only monoglyceride by molecular distillation is known. However, this method involves the recovery and re-reaction of products other than monoglyceride,
Since the equipment becomes large-scale, and purification is performed by distillation, when producing monoglycerides of various alkyl compositions, it is necessary to store the recovered products after each distillation, which imposes a heavy burden on the equipment.

On the other hand, there is also known a method of deketalizing α-monoglyceride ketal to obtain monoglyceride. As a method for synthesizing the α-monoglyceride ketal used in this method, there is a method in which glycerin is reacted with a ketone or an aldehyde and then reacted with a fatty acid. In the case, under normal esterification conditions, the ketal or acetal that is a protecting group is easily hydrolyzed by water generated by the esterification, and the product is a complex in which a hydroxyl group derived from glycerin is esterified in addition to the target product. It becomes a mixture. Also, using an enzyme instead of an acid or base catalyst,
A method of obtaining α-monoglyceride ketal in a high yield by performing a reaction under reduced pressure is also known (see JP-A-11-1).
No. 87991), equipment corresponding to the enzyme is required, and long-chain fatty acids have the disadvantage that the reaction cannot be carried out at a temperature suitable for the enzyme.

[0004] Further, a method of transesterifying glycerin ketal with glycerin ketal using a fatty acid ester instead of a fatty acid and using an alkali as a catalyst is widely known.
In this method, it is necessary to perform a two-stage operation of ketalization of glycerin and transesterification. Also, with this method,
There is a problem that it is easy to color, and furthermore, it is difficult to mix methanol produced as a by-product in esterification for use in cosmetics and the like.

An object of the present invention is to provide a simple and efficient method for producing high-purity α-monoglyceride ketal, and a method for producing α-monoglyceride using the same.

[0006]

According to the present invention, there is provided a compound represented by the general formula (1): R ¹ —COOH (1) wherein R ¹ is a hydrogen atom or a saturated or unsaturated aliphatic group having 1 to 23 carbon atoms. Shows a hydrocarbon group. And an acid represented by
(B) General formula (2) R ² —CO—R ³ (2) wherein R ² and R ³ are the same or different and are a hydrogen atom, a linear or branched alkyl group having 1 to 22 carbon atoms. Or an aryl group having a total of 6 to 30 carbon atoms which may be substituted with an alkenyl group or an alkyl group, and R ² and R ³ may combine to form a ring. A) reacting a ketone or aldehyde represented by the formula (c) with a glycerin in the presence of a catalyst.

[0007]

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Wherein R ¹ , R ² and R ³ have the above-mentioned meanings. ] And a method for producing an α-monoglyceride represented by the general formula (4), wherein the α-monoglyceride ketal obtained by the production method is deketalized.

[0009]

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Wherein R ¹ has the meaning described above. ]

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION In the component (a), R ¹ has the above-mentioned meaning, but preferably has 6 to 20 carbon atoms, especially 7 to 17 carbon atoms.
Is an aliphatic hydrocarbon group, specifically, caprylic acid,
Examples thereof include residues obtained by removing carboxyl groups from fatty acids such as lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, and isostearic acid.

In the component (b), R ² and R ³ have the above-mentioned meanings, but are preferably compounds having 1 to 10 carbon atoms in total. Specifically, acetone, methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK),
Cyclohexanone and the like; and aldehydes include formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde and the like.

The glycerin includes, in addition to glycerin, general formula (5) which is a by-product of the production method of the present invention.

[0014]

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Wherein R ² and R ³ have the above-mentioned meanings. ], And a mixture of glycerin ketal and glycerin.

In a typical method of ketalization in the present invention, the component (a) is added to the glycerin in an amount of 0.2 to 3.0 times, preferably 0.4 to 0.6 times, and the component (b) is added to a glycerin in an amount of 0.1 to 2.0 times.
2 to 3.0 times mol, preferably 1.2 to 1.5 times mol,
To facilitate separation of the generated water on the dehydration tube, preferably a solvent such as heptane, hexane, octane or the like is added at 5.0 times by weight or less, more preferably 1.0 to 2.0 times by weight, and the catalyst is added.
This is a method in which 0.01 to 5.0% by weight, preferably 0.2 to 1.0% by weight is added, and reflux dehydration is performed at a reaction temperature of 40 to 150 ° C, preferably 80 to 110 ° C under reduced pressure or normal pressure. According to such a method of the present invention, ketalization and esterification proceed simultaneously.

The catalyst used in the present invention is preferably an acid catalyst. Examples of the acid catalyst include inorganic salts such as hydrochloric acid and sulfuric acid, organic acids such as p-toluenesulfonic acid and benzenesulfonic acid, or acid clay, silica alumina and perfluorocarbon. Solid acids such as ion-exchange polymers (Nafion (manufactured by DuPont)) are exemplified.

In the reaction of the present invention, it is desirable that reflux is performed by gas-liquid contact to increase the efficiency of dehydration. After further charging the components (a), (b) and (c),
It is desirable to start heating.

After completion of the reaction, the reaction is neutralized with an alkali, or a solid acid is filtered, or the acid is adsorbed with an adsorbent, followed by filtration. Then, the solvent, unreacted ketone or aldehyde and glycerin ketal by-produced are distilled off under reduced pressure. Then, high-purity α-monoglyceride ketal can be obtained by removing unreacted glycerin and salts generated by neutralization by washing with water.

In the present invention, the α obtained as described above
-Deketalization of the monoglyceride ketal to obtain α-monoglyceride. The method of deketalization is preferably a method of hydrolyzing at a temperature of 40 to 80 ° C. and a pressure of 2.67 to 20.0 kPa using an acid catalyst, and particularly introducing steam into the reaction system.
It is preferable to carry out the reaction while removing the generated ketone and excess water vapor out of the system. As the acid catalyst, the above-mentioned catalyst used in the production of α-monoglyceride ketal can be used.

[0021]

According to the present invention, by using an acid having a desired alkyl chain length as a raw material, it is possible to synthesize an α-monoglyceride ketal in which two hydroxyl groups of α-monoglyceride are protected with a ketal or an acetal. By performing protection (deketalization), α-monoglyceride, which is widely used as an emulsifier, humectant, and industrial emulsifier for cosmetics or the like can be easily synthesized.

The method for producing the α-monoglyceride ketal of the present invention is different from the conventional method in that the number of steps is small because the coloration is small and the ketalization and esterification proceed simultaneously in the reaction step. Further, it is possible to easily obtain a monoglyceride having a mixed alkyl composition, which is difficult to obtain by a production method having a distillation step.

[0023]

EXAMPLES The percentages in the examples are by weight unless otherwise specified.

Example 1-1 A flask was charged with 350.0 g (3.80 mol) of glycerin, 399.59 g (5.70 mol) of methyl ethyl ketone, and 328.82 g of caprylic acid.
(2.28 mol), heptane (267.73 g) and paratoluenesulfonic acid (7.23 g (0.038 mol)) were charged and reacted at 86 to 107 ° C. for 14 hours while removing water produced by the reaction. next,
After neutralization with 48.5% potassium hydroxide solution, 6.66
After distilling off heptane and excess methyl ethyl ketone under reduced pressure at 50-100 ° C at kPa, glycerin ketal represented by the following formula (6) was distilled off under reduced pressure at 100-140 ° C at 0.67 kPa.
Thereafter, the remaining liquid was washed with water at 50 to 60 ° C. three times, and then dehydrated at 50 ° C. and 0.67 kPa.
450.3 g (2.06 mol) of the α-monoglyceride ketal represented by the formula was obtained. 90.47% yield, 92.1% gas chromatography purity

[0025]

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Example 1-2 α-Monoglyceride ketal 15 obtained in Example 1-1
0.3 g of paratoluenesulfonic acid monohydrate to 0 g (0.58 mol)
(0.02%, 1.58 × 10 ^-3 mol), and at 40 ° C. and 2.67 kPa, 2 to 4% of water vapor was introduced into the reaction system per hour with respect to α-monoglyceride ketal, and excess methyl ethyl ketone was formed. After 8 hours of deketalization reaction while removing water vapor outside the system, the catalyst was neutralized with an N / 2 potassium hydroxide aqueous solution, and dehydration was performed at 2.67 kPa and 60 ° C. for 0.5 hour. ) Was obtained in an amount of 125.5 g (0.57 mol) of caprylic acid monoglyceride. The yield in this deketalization reaction was 99%. Acid value 0.2 (calculated value 0), saponification value 254 (calculated value 257). As a result of analyzing the product by gas chromatography, the area percentage of caprylic acid monoglyceride was 92%. Hue G1>, APHA120.

[0027]

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Example 2-1 1672.5 g (18.16 mol) of glycerin, 1964.0 g (28.02 mol) of methyl ethyl ketone and 1880.8 g of capric acid were placed in a flask.
g (10.89 mol), heptane (1309.3 g) and paratoluenesulfonic acid (34.54 g (0.18 mol)) were charged, and the mixture was reacted at 87 to 108 ° C. for 14 hours while removing water produced by the reaction. Next, the same treatment as in Example 1-1 was performed to obtain 3237.0 g (10.76 mol) of the α-monoglyceride ketal represented by the following formula (9). 98.80% yield, 91.5% gas chroma purity

[0029]

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Example 2-2 α-Monoglyceride ketal 22 obtained in Example 2-1
2.2 g of acid clay (Galeon Earth NV, manufactured by Mizusawa Chemical Co., Ltd.) is charged to 0 g (0.73 mol), and 2 to 4% of water vapor is reacted with α-monoglyceride ketal per hour at 70 ° C. and 13.3 kPa. After being introduced into the system and performing a deketalization reaction for 7.5 hours while removing generated methyl ethyl ketone and excess water vapor out of the system, the catalyst was filtered, and 6.65 k
Dehydration was performed at 70 ° C. and Pa for 0.5 hour to obtain 169.0 g (0.69 mol) of capric acid monoglyceride represented by the following formula (10). The yield in this deketalization reaction was 94%. Acid value 0.2 (calculated value 0), saponification value 225 (calculated value 228). As a result of analyzing the product by gas chromatography, the area percentage of capric acid monoglyceride was 93%. Hue G1-2, APHA200.

[0031]

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Example 3 In a flask, 83.5 g (0.91 mol) of glycerin was added to Example 2
88.37 g (0.60 mol) of glycerin ketal recovered in Step 1, 158.89 g (2.27 mol) of methyl ethyl ketone and 15 parts of capric acid
6.52 g (0.91 mol), heptane 120.51 g and sulfuric acid 1.48 g (0.0
15 mol), and the mixture was reacted at 86 to 103 ° C. for 14 hours while removing water generated in the reaction. Next, the same treatment as in Example 1-1 was performed, except that the mixture was neutralized with a 50.0% potassium hydroxide solution, to obtain 268.4 g (0.89 mol) of the α-monoglyceride ketal represented by the above formula (9). Yield 90.47%, gas chromatography purity 90.0%.

Example 4-1 In a flask were placed 320.0 g (3.47 mol) of glycerin, 365.34 g (5.21 mol) of methyl ethyl ketone and 419.23 g of lauric acid.
(2.08 mol), heptane (244.78 g), and paratoluenesulfonic acid (6.61 g, 0.035 mol) were charged and reacted at 86 to 108 ° C. for 14 hours while removing water produced by the reaction. Next, the same treatment as in Example 1-1 was performed to obtain 661.3 g (2.14 mol) of the α-monoglyceride ketal represented by the following formula (11). Yield 96.79%, gas chromatography purity 92.3%.

[0034]

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Example 4-2 α-Monoglyceride ketal 15 obtained in Example 4-1
A deketalization reaction was carried out in the same manner as in Example 1-2 except that 0 g (0.46 mol) was used, to obtain 117.7 g (0.44 mol) of lauric acid monoglyceride represented by the following formula (12). The yield in this deketalization reaction was 89.4%. Acid value 0.3
(Calculated value 0), saponification value 205 (calculated value 204), and the product was analyzed by gas chromatography. As a result, the area percentage of lauric acid monoglyceride was 94%. Hue G1
>. APHA 100.

[0036]

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Example 5-1 A flask was charged with 128.0 g (1.39 mol) of glycerin, 146.14 g (2.08 mol) of methyl ethyl ketone, 238.24 g (0.83 mol) of isostearic acid (manufactured by Emery), 97.91 g of heptane, and 2.64 g of paratoluenesulfonic acid. g (0.014 mol), 8
The reaction was carried out at 8 to 116 ° C. for 16 hours while removing water generated by the reaction. Next, the same treatment as in Example 1-1 was performed to obtain an α-monoglyceride ketal 304 represented by the following formula (13).
4 g (0.74 mol) were obtained. Yield 88.62%, liquid chromatography purity 98%.

[0038]

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Example 5-2 α-Monoglyceride ketal 22 obtained in Example 5-1
A deketalization reaction was carried out in the same manner as in Example 1-2 except that 0 g (0.53 mol) was used to obtain 150.76 g (0.42 mol) of isostearic acid monoglyceride represented by the following formula (14).
The yield in this deketalization reaction was 89.4%. Acid value
1.10 (calculated value: 0), saponification value: 158.4 (calculated value: 156.9), and the product was analyzed by gas chromatography. As a result, the area percentage of isostearic acid monoglyceride was 98%. Hue G2. APHA 300.

[0040]

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Example 6-1 150.0 g (1.63 mol) of glycerin, 176.4 g (2.52 mol) of methyl ethyl ketone and 168.7 g (0.99 g of capric acid) were placed in a flask.
8 mol), 117.5 g of heptane and 14.69 g of Nafion-H (manufactured by DuPont) were charged and reacted at 87 to 102 ° C. for 14 hours while removing water produced by the reaction. Next, Example 1
After neutralization and removal of heptane and excess methyl ethyl ketone under reduced pressure in the same manner as in -1, glycerin ketal and capric acid were distilled off under reduced pressure at 0.33 kPa at 100 to 140 ° C.
Thereafter, the remaining liquid was washed and dehydrated in the same manner as in Example 1-1 to obtain 202.2 g (0.67 mol) of the α-monoglyceride ketal represented by the above formula (9). The yield from glycerin was 41.0%, the gas chromatographic purity was 80.0%, and glycerin ketal and capric acid were recovered and reused.

Example 6-2 The α-monoglyceride ketal 22 obtained in Example 6-1
A deketalization reaction was carried out in the same manner as in Example 2-2 except that 0 g (0.73 mol) was used, and the reaction time was changed to 8.0 hours, to obtain 161.0 g of capric acid monoglyceride represented by the above formula (10).
(0.66 mol) was obtained. The yield in this deketalization reaction is 91
%Met. The acid value was 1.0 (calculated value 0), the saponification value 220 (calculated value 228), and the product was analyzed by gas chromatography. As a result, the area percentage of capric acid monoglyceride was 78%.
Met. Hue G3.

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Kaoru Omae 1334 Minato, Wakayama-shi, Wakayama Prefecture F-term (reference) 4H006 AA02 AC41 BA66 BC10 BC11 BN10 BT12

Claims (5)

[Claims] 1. (a) R ¹ —COOH (1) wherein R ¹ represents a hydrogen atom or a saturated or unsaturated aliphatic hydrocarbon group having 1 to 23 carbon atoms. And an acid represented by
(B) General formula (2) R ² —CO—R ³ (2) wherein R ² and R ³ are the same or different and are a hydrogen atom, a linear or branched alkyl group having 1 to 22 carbon atoms. Or an aryl group having a total of 6 to 30 carbon atoms which may be substituted with an alkenyl group or an alkyl group, and R ² and R ³ may combine to form a ring. A) reacting the ketone or aldehyde represented by the formula (c) with glycerin in the presence of a catalyst. Wherein R ¹ , R ² and R ³ have the above-mentioned meaning. For producing α-monoglyceride ketal represented by the formula: 2. The method according to claim 1, wherein heating is started after charging the components (a), (b) and (c). 3. The process according to claim 1, wherein R ¹ is a saturated or unsaturated aliphatic hydrocarbon group having 6 to 20 carbon atoms. 4. The process according to claim 1, wherein the component (b) has a total carbon number of 1 to 10. 5. A method for producing α-monoglyceride represented by the general formula (4), wherein the α-monoglyceride ketal obtained by the production method according to claim 1 is deketalized. Embedded image [Wherein, R ¹ has the above-mentioned meaning. ]