JP3436450B2 - Method for producing high-purity polyglycerin fatty acid ester - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing high-purity polyglycerin fatty acid ester. The high-purity polyglycerin fatty acid ester obtained by the method of the present invention is useful as an emulsifier and a base in the fields of food, cosmetics, medicine and the like.

[0002]

2. Description of the Related Art Polyglycerin fatty acid esters are surfactants approved as food additives, and their use amount has been gradually increasing in recent years. The polyglycerin fatty acid ester is mainly obtained by reacting polyglycerin with a fatty acid or a fatty acid ester. The polyglycerin fatty acid esters are characterized in that esters having a wide range of HLB values can be obtained by variously selecting the polymerization degree of polyglycerin that functions as a hydrophilic group and the chain length of fatty acids that function as a hydrophobic group. is there. Since these esters also show high stability in the acidic region, they are widely used as emulsifiers, dispersants, viscosity modifiers, etc., especially in the food field.

Conventionally, as a method for producing this polyglycerin fatty acid ester, (1) esterification reaction of polyglycerin and fatty acids {JAOCS (Journal of American
Oil Chemists' Society) 58, 878 (1981),
JP-A-6-41007, etc.}, (2) transesterification reaction of polyglycerin with fatty acid ester,
(3) transesterification reaction between polyglycerin and fats and oils, (4)
Addition polymerization reaction of glycidol with fatty acid monoglycerides {see USP 4,515,775}, (5) Addition polymerization reaction of glycidol with fatty acids (JP-A-51-65)
No. 705), etc. are known.

[0004]

[Problems to be Solved by the Invention] When polyglycerin fatty acid esters are produced by the above methods (1) to (3), unreacted polyglycerin remains in the product. Since both polyglycerin fatty acid esters and polyglycerin have extremely high boiling points and cannot be efficiently separated by a costly molecular distillation method, ordinary polyglycerin fatty acid esters are not reacted with unreacted polyglycerin. It is marketed in the form of a product containing. Since unreacted polyglycerin itself does not have an emulsifying function, products containing a large amount of these are markedly reduced in surface tension, dispersive power, bubble power, and emulsion stability. .

Polyglycerin fatty acid esters are
When the method (4) to (5) is used for production, it is possible to avoid mixing unreacted polyglycerin into the product, but there is a problem that unreacted glycidol is mixed. Unreacted glycidol, like unreacted polyglycerin, does not have an emulsifying function by itself, so products containing a large amount of these should have a reduced surface tension, reduced dispersive power, reduced bubble power, and emulsion stability. Is noticeably reduced. In order to remove unreacted glycidol from polyglycerin fatty acid esters, it is necessary to distill by a molecular distillation method. This distillation method is uneconomical and not preferable for industrial implementation.

Under these circumstances, when it is applied to a surfactant or an emulsion stabilizer in the food field, it is expected to improve surface tension, dispersion power, bubble power, and emulsion stability. There has been a demand for a method for producing high-purity polyglycerin fatty acid esters which does not contain reacted polyglycerin, unreacted glycidol, or the like, or whose content is extremely small even if they are contained.

[0007]

Means for Solving the Problems The present invention is to solve the problems existing in the above-mentioned prior art, and does not contain unreacted polyglycerin, unreacted glycidol, etc. The present invention provides a method for producing extremely low-purity polyglycerin fatty acid esters.
That is, according to the present invention, the first step of obtaining a polyglycerol fatty acid ester by the addition polymerization reaction of a fatty acid having 7 to 22 carbon atoms and glycidol, water is added to the product obtained in this first step, A method for producing a high-purity polyglycerin fatty acid ester is provided, which comprises a second step of heating and then dehydrating.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is described in detail below.
In the method of the present invention, in a first step, obtaining a fatty acid and glycidol and the addition polymerization reaction is allowed to polyglycerol fatty acid ester, as a raw material of the fatty acid used herein, using fatty acids 7 to 22 carbon atoms Rukoto is Ru essential der. The fatty acid may be a saturated fatty acid or an unsaturated fatty acid, may be a linear fatty acid or a fatty acid having a side chain, and may be a substituted fatty acid having a carbon chain substituted with a hydroxyl group. Specific examples of these fatty acids include caprylic acid and 2-
Ethylhexanoic acid, capric acid, lauric acid, isotridecanoic acid, myristic acid, palmitic acid, palmitoleic acid, stearic acid, isostearic acid, oleic acid,
Examples thereof include linoleic acid, behenic acid, erucic acid, ricinoleic acid and hydroxystearic acid. These may be used alone or in any combination of two or more.

The molar ratio of glycidol to fatty acid in the addition polymerization reaction of glycidol and fatty acid is 0.8 to
It is preferable to select in the range of 1.3, and it is particularly preferable to select in the range of 1.0 to 1.1.

The addition polymerization reaction of the above fatty acid and glycidol is preferably carried out in the presence of a phosphoric acid-based acidic catalyst, if necessary, in the presence of a solvent. The phosphoric acid-based acidic catalyst used here is phosphoric acid or phosphoric acid ester. Specifically, phosphoric acid, phosphoric anhydride, polyphosphoric acid, orthophosphoric acid, metaphosphoric acid, pyrophosphoric acid, phosphoric acid such as triphosphoric acid, tetraphosphoric acid, methyl acid phosphate, ethyl acid phosphate, isopropyl acid phosphate, butyl acid. Phosphate, 2-
Examples thereof include acidic phosphoric acid esters such as ethylhexyl acid phosphate. The acidic phosphoric acid ester may be a monoester body, a diester body or a mixture thereof. Among the catalysts listed above, phosphoric acid and acidic phosphoric acid esters are particularly preferable.

The above catalysts may be used alone or in admixture of two or more. The amount of the catalyst used was 0.
It is preferable to select in the range of 01 to 10% by weight. If it is less than 0.01% by weight, the reaction rate is too slow, and if it exceeds 10% by weight, the effect is not reached even if a large amount of the catalyst is used, and an addition polymer of glycidol is by-produced. Absent. In the above range of the amount of catalyst used, 0.1-5
Weight percent is particularly preferred.

Although the addition polymerization reaction can be carried out without a solvent,
A solvent may be used. As the solvent that can be used, aromatic hydrocarbons having 6 to 9 carbon atoms, particularly halogenated toluene such as benzene, toluene and trifluorotoluene, aliphatic ketones having 3 to 9 carbon atoms, especially methyl isopropyl ketone , Methyl isobutyl ketone, diethyl ketone, di-isobutyl ketone, and the like. Besides, ethers such as diisopropyl ether are also suitable. These solvents may be used alone or as a mixture of two or more kinds. When using a solvent, the amount used is preferably as small as possible from the viewpoint of recovery operation after completion of the reaction, and particularly preferably twice the total amount of the reaction raw materials.

The reaction temperature varies depending on the presence or absence of a solvent, the type and amount of the catalyst, and the like, but it is preferably selected in the range of 50 to 180 ° C. If the temperature is lower than 50 ° C, the reaction rate is too slow, and if it exceeds 180 ° C, not only the coloring of the product becomes severe, but also glycidol is decomposed to cause a side reaction, which is not preferable. In the above temperature range, 70 to 160 ° C is preferable, and 140 to 160 ° C is particularly preferable.

The addition polymerization reaction is preferably carried out by mixing the fatty acid, the solvent and the catalyst in a reaction vessel, heating the mixture to the reaction temperature, and then adding glycidol little by little with stirring. The reaction can be carried out continuously or batchwise. When a solvent is used and its boiling point is below the reaction temperature, it is advantageous to carry out under pressure. It is desirable to carry out the addition polymerization reaction in an inert gas atmosphere such as nitrogen gas.

By the above reaction, glycidol is addition-polymerized with the fatty acid to produce a polyglycerin fatty acid ester having a higher degree of polymerization. The product is a monofatty acid ester form,
The polyglycerin fatty acid ester is a mixture of di-fatty acid ester body and tri-fatty acid ester body, and according to the above reaction, one having a large content ratio of mono fatty acid ester body is obtained. That is, the polyglycerin fatty acid ester obtained by the present invention has a content of 70% or more represented by the peak area ratio of the monofatty acid ester body detected by an ultraviolet absorption detector by a column chromatography analysis method. .

In the production method of the present invention, it is essential that water is added to the polyglycerin fatty acid ester obtained in the first step, followed by heating and dehydration in the second step. By this second step, the unreacted glycidol contained in the polyglycerin fatty acid ester can be reduced, and a high-purity target product can be obtained.

In the second step, the amount of water added is preferably selected in the range of 0.1 to 20% by weight based on the polyglycerin fatty acid ester obtained in the first step. If the amount of water is less than 0.1% by weight, unreacted glycidol cannot be sufficiently reduced, and if it exceeds 20% by weight, the post-treatment operation becomes complicated, which is not preferable.
A particularly preferable range of the amount of water to be added is 1 to 10% by weight.
Is.

In the second step, after adding water to the polyglycerol fatty acid ester obtained in the first step,
To heat. By heating, unreacted glycidol can be converted into glycerin. The heating temperature at this time is preferably selected in the range of 60 to 200 ° C. If the heating temperature is lower than 60 ° C, unreacted glycidol cannot be sufficiently reduced, and if it exceeds 200 ° C, the polyglycerin fatty acid ester of the product is colored, which is not preferable. Particularly preferably in the above temperature range, 80 to
It is in the range of 160 ° C. The heating time depends on the temperature,
It is in the range of 0.5 to 15 hours, particularly preferably 1 to 7 hours.

In the second step, dehydration is performed after the above heat treatment operation. Dehydration can be performed by distillation, azeotropic distillation, vacuum distillation, or the like. The heating temperature for distillation is 100 to 20.
It is preferable to select in the range of 0 ° C. If the heating temperature is lower than 100 ° C, it is not sufficient to remove the water contained in the polyglycerin fatty acid ester of the product, and if the heating temperature exceeds 200 ° C, the product polyglycerin fatty acid ester is colored, which is not preferable. . Particularly preferable temperature range is 110 to 160 ° C. Dehydration time is
Depending on the temperature and the degree of reduced pressure, it is selected within the range of 1 to 10 hours. Among them, the range of 1 to 6 hours is preferable. The solvent used in the first step can be removed by this dehydration operation, but can also be removed by an operation other than the dehydration operation.

As described above, according to the method of the present invention, the carbon number
A highly pure polyglycerin fatty acid ester can be obtained by an addition polymerization reaction of 7 to 22 fatty acids and glycidol. The amount of unreacted glycidol can be ascertained by measuring the oxirane oxygen concentration on the product.

High-purity polyglycerin fatty acid ester obtained by the method of the present invention (hereinafter simply referred to as "high-purity product")
May be described as. ) Has a content of mono-fatty acid ester of 70% by weight or more and is used for various uses in which polyglycerin fatty acid ester has been conventionally used, and can sufficiently exert its intended function. Hereinafter, these applications will be briefly illustrated.

(1) The "high-purity product" obtained by the method of the present invention is used as a surfactant for fats and oils for the production of breads, cakes and confectioneries (JP-A-6-53 and JP-A-6-53). No. 22690, No. 6-78672, No. 6-253718, No. 6-269.
244, etc.). (2) The "high-purity product" obtained by the method of the present invention is
Used as an emulsion stabilizer for cocoa drinks (Japanese Patent Laid-Open No. 6-
See 38682). (3) The “high-purity product” obtained by the method of the present invention is
Used as a quality improver for noodles (JP-A-6-1977).
17 and JP-A-6-276972, etc.).

(4) The "high-purity product" obtained by the method of the present invention is used as a quality improving agent for fish paste products (JP-A-6-22730 and JP-A-6-9071).
(See No. 3, etc.). (5) Used as a substitute for a plasticizer for the production of enteric-coated lactic acid bacterium granules (see JP-A-6-133735). (6) Used as an emulsifier of an oil-in-water type emulsified oil / fat composition (see JP-A-6-209704).

(7) It is used as an emulsifier for an oil / fat having a flavor or an oil / fat composition to which a flavor component is added (see JP-A-6-14711). (8) Used as a fat dispersion emulsification accelerator for sour cheese beverages (see JP-A-6-113799). (9) Used as an emulsifier for a food freshness-retaining agent (see JP-A-6-153884). (10) Used as a blend of a composition for improving the quality of a fluid starch food (see JP-A-6-225684).

(11) Used as an additive for fat-containing lactic acid beverages (see JP-A-6-62734). (12) Used as an emulsifier for water-containing chocolates (see JP-A-6-189682). (13) Used as an emulsifier for coffee cream (see JP-A-6-90663). (14) Used as an emulsifier for an oil-in-water type emulsion for producing fish ham (see JP-A-6-113727).

[0026]

EXAMPLES The present invention will be described below in detail based on examples, but the present invention is not limited to the following examples.

Example 1 <First Step> A 1-liter 4-necked flask equipped with a stirrer, a thermometer, a temperature controller, a reflux condenser, a dropping cylinder, a nitrogen gas introduction tube, and the like was charged with 0 lauric acid. 0.5 mol (100.16 g) and phosphoric acid (purity 85% product) 0.06
22 g was charged, and the internal temperature was heated to 140 ° C. with stirring.
Next, while maintaining the internal temperature at this temperature and stirring, 3.0 mol (222.24 g) of glycidol was added dropwise over 5 hours, and the reaction was continued until the oxirane concentration in the system reached 0.067%. The acid value of the reaction product of this first step is
It was 0.13.

[0028] After completion <Second Step> The first step was added 2% by weight based on the contents of the flask water into the same flask, heated under stirring, the internal temperature of the flask to 120 ° C., under reflux, the temperature Held for 2 hours. Next, the temperature inside the flask was raised to 140 ° C., and while maintaining this temperature, the inside of the flask was depressurized and vacuum distillation was performed to dehydrate. Vacuum distillation 4
The final degree of vacuum was 10 mmHg when the operation was performed for a while.
The polyglycerin fatty acid ester obtained had an oxirane concentration of 0.043 and an acid value of 0.45.

[Example 2] <First step> The same as the example described in Example 1. <Second Step> After the completion of the first step, 2% by weight of water was added to the same flask in the same manner as in Example 1, the flask inner temperature was heated to 120 ° C. under stirring, and the mixture was refluxed at this temperature for 6%. Held for hours. Next, the temperature inside the flask is raised to 140 ° C.,
While maintaining this temperature, the inside of the flask was decompressed and distilled under reduced pressure to dehydrate. The final degree of vacuum was 10 mmHg after vacuum distillation for 4 hours. The obtained polyglycerin fatty acid ester had an oxirane concentration of 0.026 and an acid value of 0.45.

[Example 3] <First step> The same as the example described in Example 1 was applied. <Second Step> After the completion of the first step, 2% by weight of water was added to the same flask as in Example 1, the flask internal temperature was heated to 135 ° C. under stirring, and the mixture was refluxed at this temperature for 2 hours. Held for hours. Next, the temperature inside the flask is raised to 140 ° C.,
While maintaining this temperature, the inside of the flask was decompressed and distilled under reduced pressure to dehydrate. The final degree of vacuum was 10 mmHg after vacuum distillation for 4 hours. The obtained polyglycerin fatty acid ester has an oxirane concentration of 0.0072,
The acid value was 0.45.

Example 4 <First Step> The same as the example described in Example 1 was applied. <Second Step> After the completion of the first step, 2% by weight of water was added to the same flask in the same manner as in Example 1, the flask internal temperature was heated to 140 ° C. under stirring, and the mixture was refluxed at this temperature for 2 hours. Held for hours. Next, the temperature inside the flask is raised to 140 ° C.,
While maintaining this temperature, vacuum was applied to the flask for vacuum distillation to dehydrate. When vacuum distillation was performed for 4 hours,
The final degree of vacuum was 10 mmHg. The obtained polyglycerin fatty acid ester has an oxirane concentration of 0.007.
2, the acid value was 0.45.

INDUSTRIAL APPLICABILITY The present invention has the following special advantageous effects and its industrial utility value is extremely large. 1. According to the method of the present invention, extremely high-purity polyglycerol fatty acid ester can be industrially produced without relying on the economically disadvantageous molecular distillation method. 2. According to the method of the present invention, when passing through the first step and the second step, a highly pure polyglycerin fatty acid ester having a lower oxirane concentration than a product not passing through the second step can be obtained. 3. High-purity polyglycerin fatty acid ester obtained by the method of the present invention is a surfactant, when applied to an emulsion stabilizer in the food field, the surface tension is improved, the dispersibility is improved, the foaming power is improved, and the emulsion stability is improved. A significant improvement is achieved.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ identification code FI // C07B 61/00 300 C07B 61/00 300 (58) Fields surveyed (Int.Cl. ⁷ , DB name) C08G 65/26 -65/30 C07C 67/08 C07C 69/30 C11C 3/02 C07B 61/00

Claims (5)

(57) [Claims] 1. A first step for obtaining a polyglycerin fatty acid ester by subjecting a fatty acid having 7 to 22 carbon atoms and glycidol to an addition polymerization reaction, and after adding water to the product obtained in the first step and heating the product. The method for producing high-purity polyglycerol fatty acid ester is characterized by comprising the second step of dehydration. 2. The method for producing a high-purity polyglycerin fatty acid ester according to claim 1, wherein the addition polymerization reaction in the first step is carried out in the presence of a phosphoric acid-based acidic catalyst. 3. The addition polymerization reaction of the first step is carried out at 50-18.
The method for producing a high-purity polyglycerin fatty acid ester according to claim 1 or 2, which is performed in a temperature range of 0 ° C. 4. The method according to claim 1, wherein the amount of water added in the second step is in the range of 0.1 to 20% by weight based on the polyglycerin fatty acid ester obtained in the first step. The method for producing the high-purity polyglycerin fatty acid ester according to 1. 5. The method for producing a high-purity polyglycerin fatty acid ester according to claim 1, wherein the high-purity polyglycerin fatty acid ester has a mono-fatty acid ester content of 70% by weight or more.