Synthesis method of fatty acid polyglycerol ester

Abstract

The invention relates to a synthesis method of fatty acid polyglycerol ester, and mainly solves the technical problem that in the prior art, fatty acid and polyglycerol ester are subjected to esterification reaction under the condition of a catalyst, and an obtained fatty acid polyglycerol ester product is deep in chromaticity. Comprising the following steps: (1) mixing fatty acid, polyglycerol, a component A and a component B to obtain a material I; (2) reacting the material I under an esterification condition to obtain a material containing fatty acid polyglycerol ester; wherein the component A is alkali, the component B comprises at least one selected from a substance group consisting of polyoxyethylene sorbitan fatty acid ester, alkyl glycoside and polyethylene glycol, and the synthetic method has the advantage that the obtained fatty acid polyglycerol ester product is small in chroma.

Description

Technical Field

[0001] The present invention relates to a method for synthesizing fatty acid polyglycerol ester. Background Art

[0002] Fatty acid polyglycerol esters are products obtained by the esterification reaction of fatty acids with polyglycerol in the presence of a catalyst. Their emulsifying properties are far superior to monoglycerides because they have more hydrophilic hydroxyl groups and polar ether bonds. Their hydrophilicity increases with increasing glycerol polymerization degree, while their lipophilicity varies with the fatty acid alkyl groups. Therefore, by varying the polyglycerol polymerization degree, fatty acid type, and degree of esterification, a range of polyglycerol ester products with HLB values ​​ranging from 1 to 20, from lipophilic to hydrophilic, can be produced to suit various specific applications. However, the esterification of fatty acids with polyglycerol to produce polyglycerol fatty acid esters can result in a product with high color. To meet demanding requirements for low color, decolorization with a decolorant (such as hydrogen peroxide) is often necessary to reduce the product's color. Furthermore, the higher the color, the higher the decolorization load, which can lead to, for example, but not limited to, a higher decolorant dosage. Summary of the Invention

[0003] The present invention aims to solve the technical problem that in the prior art, fatty acids and polyglycerol esters are subjected to esterification reaction to obtain fatty acid polyglycerol ester products with deep chroma, and provides a method for synthesizing fatty acid polyglycerol esters. The synthesis method has the advantage that the obtained fatty acid polyglycerol ester products have low chroma.

[0004] In order to solve the above technical problems, the technical solutions of the present invention are as follows:

[0005] The synthetic method of fatty acid polyglycerol ester comprises the following steps:

[0006] (1) mixing fatty acid, polyglycerol, component A and component B to obtain material I;

[0007] (2) reacting material I under esterification conditions to obtain a material containing fatty acid polyglycerol ester;

[0008] Component A is a base, and component B includes at least one selected from the group consisting of polyoxyethylene sorbitan fatty acid esters, alkyl glycosides, and polyethylene glycol.

[0009] The addition of component B reduces the chromaticity of the product.

[0010] The selection of the key component B and the related process conditions of the method of the present invention can be reasonably selected by those skilled in the art without having to make any creative efforts. The following process conditions and technical solutions are only examples or preferences.

[0011] In the above technical solution, component A is preferably an alkali metal hydroxide or an alkali metal carbonate.

[0012] In the above technical solution, preferably the alkali metal is potassium or sodium.

[0013] In step (1), in order to obtain material I, the mixing order of each component can be carried out according to the understanding of those skilled in the art, and there is no particular restriction on this, and comparable technical effects can be obtained. However, it is also clear to those skilled in the art that when component B contains polyoxyethylene sorbitan fatty acid ester, alkali metal carbonate, especially alkali metal hydroxide, contacts with polyoxyethylene sorbitan fatty acid ester for a long time and can cause polyoxyethylene sorbitan fatty acid ester saponification, thereby reducing the effect of component B. Therefore, it is necessary to avoid alkali, especially alkali metal hydroxide, from contacting with polyoxyethylene sorbitan fatty acid ester for a long time as much as possible.

[0014] When component B comprises polyoxyethylene sorbitan fatty acid ester, a recommended mixing method includes, but is not limited to, first mixing the base or a material containing the base with the fatty acid or a material containing the fatty acid to neutralize the base, and then mixing with the polyoxyethylene sorbitan fatty acid ester or a material containing the polyoxyethylene sorbitan fatty acid ester. Alternatively, the polyoxyethylene sorbitan fatty acid ester may be first mixed with a material comprising a fatty acid, and then the base or the base-containing material may be added, so that the base and the fatty acid undergo an instantaneous neutralization reaction. This avoids prolonged contact between the base and the polyoxyethylene sorbitan fatty acid ester.

[0015] In the above technical solution, the polyoxyethylene sorbitan fatty acid ester is preferably at least one selected from the group consisting of Tween 20, Tween 40, Tween 60, Tween 80 and Tween 85.

[0016] In the above technical solution, the fatty acid is preferably a C8-C18 fatty acid. For example, the fatty acid is at least one selected from the group consisting of C8 fatty acids, C9 fatty acids, C10 fatty acids, C11 fatty acids, C12 fatty acids, C13 fatty acids, C14 fatty acids, C15 fatty acids, C16 fatty acids, C17 fatty acids, and C18 fatty acids. For comparison purposes only, the fatty acids used in the Examples and Comparative Examples are commercially available coconut oil fatty acids with an acid value of 273.1 mgKOH / g (based on a molecular weight of 205 g / mol), and the acid value is determined according to GB / T 6365-2006 (Determination of Free Alkalinity or Free Acidity of Surfactants - Titration Method).

[0017] In the above technical solution, the degree of polymerization n of the polyglycerol is preferably 2 to 10. For example, the polyglycerol is at least one selected from the group consisting of diglycerol, triglycerol, tetraglycerol, pentaglycerol, hexaglycerol, heptaglycerol, octaglycerol, nonaglycerol, and decaglycerol.

[0018] Glycerol can be regarded as n=1, and the number of hydroxyl groups in the molecule is 3; diglycerol, n=2, and the number of hydroxyl groups in the molecule is 4; trimerol, n=3, and the number of hydroxyl groups in the molecule is 5, ..., so when the degree of polymerization of glycerol is n, the number of hydroxyl groups in the molecule is n+2.

[0019] In the above technical solution, the weight ratio of component A to component B is preferably 0.01 to 100, for example but not limited to 0.02, 0.05, 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, etc., more preferably 0.02 to 50, even more preferably 0.05 to 20, and most preferably 0.1 to 10.

[0020] In the above technical solution, based on the total weight of the esterification raw materials composed of fatty acids and polyglycerol, component A is preferably 0.05-0.8% of the total weight of the esterification raw materials, for example but not limited to 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7% and the like, more preferably 0.05-0.5%.

[0021] In the above technical solutions, Tween is better than alkyl glycoside, alkyl glycoside is better than polyethylene glycol, while fatty alcohol polyoxyethylene ether has no effect, and the use of sodium dodecylbenzenesulfonate will increase the color of the product.

[0022] In the above technical solution, component B preferably includes both polyoxyethylene sorbitan fatty acid ester and alkyl glycoside. Polyoxyethylene sorbitan fatty acid ester and alkyl glycoside have a mutually reinforcing effect in reducing product color. For example only, the weight ratio of polyoxyethylene sorbitan fatty acid ester to alkyl glycoside is 0.01 to 100, for example but not limited to 0.02, 0.05, 0.1, 0.2, 0.5, 1, 1.5, 2, 3, 4, 5, 6, 7, 8, 9, 10, etc., more preferably 0.02 to 50, even more preferably 0.05 to 20, and most preferably 0.05 to 10.

[0023] The alkyl group in the alkyl glycoside is preferably a C8-C18 alkyl group. For example, but not limited to, a C8 alkyl group, a C9 alkyl group, a C10 alkyl group, a C11 alkyl group, a C12 alkyl group, a C13 alkyl group, a C14 alkyl group, a C15 alkyl group, a C16 alkyl group, a C17 alkyl group, a C18 alkyl group, and the like. The alkyl alcohol used in the preparation of the corresponding alkyl glycoside is preferably at least one selected from the group consisting of a C8 alkyl alcohol, a C9 alkyl alcohol, a C10 alkyl alcohol, a C11 alkyl alcohol, a C12 alkyl alcohol, a C13 alkyl alcohol, a C14 alkyl alcohol, a C15 alkyl alcohol, a C16 alkyl alcohol, a C17 alkyl alcohol, and a C18 alkyl alcohol.

[0024] The average degree of polymerization of the glycosyl group in the alkyl glycoside is preferably 1.1 to 3, for example but not limited to 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.2, 2.4, 2.6, 2.8, etc.

[0025] By way of example only, the alkyl glycoside can be, for example, an alkyl glucoside.

[0026] For comparison purposes only, the alkyl glycosides in the examples and comparative examples are all dodecyl glucoside, and the average degree of polymerization of the glycosyl group is 1.6.

[0027] In the above technical solution, the molar ratio of the fatty acid to the polyglycerol is preferably 1 to (n+2). For example, but not limited to, when n=2, the molar ratio is 1.5, 2, 2.5, 3, 3.5, 4, etc.; when n=3, the molar ratio is 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, etc.; when n=4, the molar ratio is 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, etc.

[0028] In the above technical solution, the preferred reaction temperature is 100-230°C, for example but not limited to 110°C, 120°C, 130°C, 140°C, 150°C, 160°C, 170°C, 180°C, 190°C, 200°C, 210°C, 220°C, and the like.

[0029] In the above technical solution, the reaction time is preferably 1 to 10 hours. For example, but not limited to, the esterification time is 1 hour, 1.5 hours, 2 hours, 2.5 hours, 3 hours, 3.5 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, etc.

[0030] The method for determining the saponification value of fatty acid polyglycerol ester products is HG / T 3505-2020 (Determination of the Saponification Value of Surfactants).

[0031] The chromaticity of the product in the specific embodiment of the present invention is measured using the method of GB / T 22295-2008 (Test method for color of transparent liquids (Gardner colorimeter)).

[0032] The inventors have found through experiments that the synthesis method of the present invention has the advantage of low chroma and a high yield of fatty acid polyglycerol ester (under comparable conditions, a higher saponification value of the product indicates a higher yield).

[0033] The present invention will be further described below with reference to the embodiments. DETAILED DESCRIPTION

[0034] [Comparative Example 1]

[0035] Stir with band, drop into 331g (1.6 moles) fatty acid and 169g (1.0 moles) dipolyglycerol in 1 liter of four-hole boiling flask of nitrogen bubbling tube and electric heating jacket, add 1.0g sodium hydroxide again, seal each interface, open and stir, rotating speed is 300r / min, open nitrogen, nitrogen flow is 1L / min, start to heat up, heating rate is 4 ℃ / min, until temperature arrives 200 ℃, keep rotating speed 300r / min, 200 ℃ of constant temperature three hours under nitrogen flow 1L / min, start cooling, cooling rate is 1.5 ℃ / min, until temperature is reduced to 100 ℃, adding 1.0g weight concentration is 85% phosphoric acid neutralization, obtains fatty acid polyglycerol ester product.

[0036] The saponification value of the product is 182.1 mgKOH / g, and the Gardner color value of the product is 7.

[0037] [Comparative Example 2]

[0038] Stir in band, drop into 331g (1.6 moles) lipid acid and 169g (1.0 moles) two Polyglycerol in 1 liter of four-hole boiling flask of nitrogen bubbling tube and electric heating jacket, add 1.0g sodium hydroxide, add 0.50g PEG400 again, seal each interface, open and stir, rotating speed is 300r / min, open nitrogen, nitrogen flow is 1L / min, begin to heat up, heating rate is 4 ℃ / min, until temperature arrives 200 ℃, keep rotating speed 300r / min, 200 ℃ of constant temperature three hours under nitrogen flow 1L / min, begin to cool, cooling rate is 1.5 ℃ / min, until temperature is reduced to 100 ℃, adding the 1.0g weight concentration is 85% phosphoric acid neutralization, obtains fatty acid polyglycerol ester product.

[0039] The saponification value of the product is 183.5 mgKOH / g, and the Gardner color value of the product is 6.

[0040] [Comparative Example 3]

[0041] 331 g (1.6 mol) of fatty acid and 169 g (1.0 mol) of dipolyglycerol were added to a 1-liter four-necked flask with stirring, a nitrogen bubbling tube and an electric heating jacket, 1.0 g of sodium hydroxide was added, and then 0.50 g of AEO-9 was added. The interfaces were sealed, stirring was started at a speed of 300 r / min, nitrogen was turned on, and a nitrogen flow rate of 1 L / min was set. The temperature was started at a heating rate of 4°C / min until the temperature reached 200°C. The temperature was maintained at 200°C for three hours at a speed of 300 r / min and a nitrogen flow rate of 1 L / min. The temperature was then lowered at a cooling rate of 1.5°C / min until the temperature dropped to 100°C. 1.0 g of phosphoric acid with a weight concentration of 85% was added for neutralization to obtain a fatty acid polyglycerol ester product.

[0042] The saponification value of the product is 184.3 mgKOH / g, and the Gardner color value of the product is 7.

[0043] [Comparative Example 4]

[0044] Stirring with band, drop into 331g (1.6 moles) fatty acid and 169g (1.0 moles) dipolyglycerol in 1 liter of four-hole boiling flask of nitrogen bubbling tube and electric heating jacket, add 1.0g sodium hydroxide, add 0.50g sodium dodecylbenzene sulfonate again, seal each interface, open and stir, rotating speed is 300r / min, open nitrogen, nitrogen flow is 1L / min, start to heat up, heating rate is 4 ℃ / min, until temperature arrives 200 ℃, keep rotating speed 300r / min, 200 ℃ of constant temperature three hours under nitrogen flow 1L / min, start cooling, cooling rate is 1.5 ℃ / min, until temperature is reduced to 100 ℃, adding 1.0g weight concentration is 85% phosphoric acid neutralization, obtains fatty acid polyglycerol ester product.

[0045] The saponification value of the product is 183.7 mgKOH / g, and the Gardner color value of the product is 8.

[0046] [Example 1]

[0047] Stirring with band, drop into 1 liter of four-hole boiling flask of nitrogen bubbling tube and electric heating jacket 331g (1.6 moles) fatty acid and 169g (1.0 moles) dipolyglycerol, add 1.0g sodium hydroxide, then add 0.50g Tween 80, seal each interface, open and stir, rotating speed is 300r / min, open nitrogen, nitrogen flow is 1L / min, start to heat up, heating rate is 4 ℃ / min, until temperature arrives 200 ℃, keep rotating speed 300r / min, 200 ℃ of constant temperature three hours under nitrogen flow 1L / min, start cooling, cooling rate is 1.5 ℃ / min, until temperature is reduced to 100 ℃, adding 1.0g weight concentration is 85% phosphoric acid neutralization, obtains fatty acid polyglycerol ester product.

[0048] The saponification value of the product is 185.8 mgKOH / g, and the Gardner color value of the product is 5-.

[0049] [Example 2]

[0050] Stirring with band, drop into 1 liter of four-necked flask of nitrogen bubbling tube and electric heating jacket 331g (1.6 moles) fatty acid and 169g (1.0 moles) dipolyglycerol, add 1.0g sodium hydroxide, then add 0.50g alkyl glycoside, seal each interface, open and stir, rotating speed is 300r / min, open nitrogen, nitrogen flow is 1L / min, start to heat up, heating rate is 4 ℃ / min, until temperature arrives 200 ℃, keep rotating speed 300r / min, 200 ℃ of constant temperatures three hours under nitrogen flow 1L / min, start cooling, cooling rate is 1.5 ℃ / min, until temperature is reduced to 100 ℃, adding 1.0g weight concentration is 85% phosphoric acid neutralization, obtains fatty acid polyglycerol ester product.

[0051] The saponification value of the product is 185.2 mgKOH / g, and the Gardner color value of the product is 5.

[0052] [Example 3]

[0053] 331g (1.6 moles) fatty acid and 169g (1.0 mole) dipolyglycerol are dropped into 1 liter of four-necked flask with stirring, nitrogen bubbling tube and electric heating jacket, 1.0g sodium hydroxide is added, then 0.40g Tween 80 and 0.10g alkyl glycoside are added, each interface is sealed, and stirring is opened, and rotating speed is 300r / min, and nitrogen is opened, and nitrogen flow rate is 1L / min, and heats up, and heating rate is 4 ℃ / min, until temperature arrives 200 ℃, keeps rotating speed 300r / min, 200 ℃ of constant temperatures under nitrogen flow rate 1L / min three hours, starts cooling, and cooling rate is 1.5 ℃ / min, until temperature is reduced to 100 ℃, adding 1.0g weight concentration is 85% phosphoric acid and neutralizes, obtains fatty acid polyglycerol ester product.

[0054] The saponification value of the product is 188.4 mgKOH / g, and the Gardner color value of the product is 2+.

[0055] [Example 4]

[0056] 331g (1.6 moles) fatty acid and 169g (1.0 mole) dipolyglycerol are dropped into 1 liter of four-necked flask with stirring, nitrogen bubbling tube and electric heating jacket, 1.0g sodium hydroxide is added, then 0.30g Tween 80 and 0.20g alkyl glycoside are added, each interface is sealed, and stirring is opened, and rotating speed is 300r / min, and nitrogen is opened, and nitrogen flow rate is 1L / min, and heats up, and heating rate is 4 ℃ / min, until temperature arrives 200 ℃, keeps rotating speed 300r / min, constant temperature is 200 ℃ under nitrogen flow rate 1L / min for three hours, starts cooling, and cooling rate is 1.5 ℃ / min, until temperature drops to 100 ℃, adds 1.0g weight concentration and is 85% phosphoric acid neutralization, obtains fatty acid polyglycerol ester product.

[0057] The saponification value of the product is 190.4 mgKOH / g, and the Gardner color value of the product is 2.

[0058] [Example 5]

[0059] Stir with band, drop into 1 liter of four-hole boiling flask of nitrogen bubbling tube and electric heating jacket 331g (1.6 moles) fatty acid and 169g (1.0 moles) dipolyglycerol, add 1.0g sodium hydroxide, then add 0.25g Tween 80 and 0.25g alkyl glycoside, seal each interface, open and stir, rotating speed is 300r / min, open nitrogen, nitrogen flow is 1L / min, start to heat up, heating rate is 4 ℃ / min, until temperature arrives 200 ℃, keep rotating speed 300r / min, 200 ℃ of constant temperatures three hours under nitrogen flow 1L / min, start cooling, cooling rate is 1.5 ℃ / min, until temperature is reduced to 100 ℃, adding 1.0g weight concentration is 85% phosphoric acid neutralization, obtains fatty acid polyglycerol ester product.

[0060] The saponification value of the product is 186.3 mgKOH / g, and the Gardner color value of the product is 3+.

[0061] [Example 6]

[0062] 331g (1.6 moles) fatty acid and 169g (1.0 mole) dipolyglycerol are dropped into 1 liter of four-necked flask with stirring, nitrogen bubbling tube and electric heating jacket, 1.0g sodium hydroxide is added, then 0.20g Tween 80 and 0.30g alkyl glycoside are added, each interface is sealed, and stirring is opened, and rotating speed is 300r / min, and nitrogen is opened, and nitrogen flow rate is 1L / min, and heats up, and heating rate is 4 ℃ / min, until temperature arrives 200 ℃, keeps rotating speed 300r / min, constant temperature is 200 ℃ under nitrogen flow rate 1L / min for three hours, starts cooling, and cooling rate is 1.5 ℃ / min, until temperature drops to 100 ℃, adding 1.0g weight concentration is 85% phosphoric acid and neutralizes, obtains fatty acid polyglycerol ester product.

[0063] The saponification value of the product is 188.6 mgKOH / g, and the Gardner color value of the product is 4.

[0064] [Example 7]

[0065] 331g (1.6 moles) fatty acid and 169g (1.0 mole) dipolyglycerol are dropped into 1 liter of four-necked flask with stirring, nitrogen bubbling tube and electric heating jacket, 1.0g sodium hydroxide is added, then 0.10g Tween 80 and 0.40g alkyl glycoside are added, each interface is sealed, and stirring is opened, and rotating speed is 300r / min, and nitrogen is opened, and nitrogen flow rate is 1L / min, and heats up, and heating rate is 4 ℃ / min, until temperature arrives 200 ℃, keeps rotating speed 300r / min, constant temperature is 200 ℃ under nitrogen flow rate 1L / min for three hours, starts cooling, and cooling rate is 1.5 ℃ / min, until temperature is reduced to 100 ℃, adding 1.0g weight concentration is 85% phosphoric acid and neutralizes, obtains fatty acid polyglycerol ester product.

[0066] The saponification value of the product is 187.5 mgKOH / g, and the Gardner color value of the product is 4+.

Claims

1. The synthetic method of fatty acid polyglycerol ester comprises the following steps: (1) mixing fatty acid, polyglycerol, component A and component B to obtain material I; (2) reacting material I under esterification conditions to obtain a material containing fatty acid polyglycerol ester; Component A is a base, and component B includes at least one selected from the group consisting of polyoxyethylene sorbitan fatty acid esters, alkyl glycosides, and polyethylene glycol.

2. The synthetic method according to claim 1, wherein Component A is an alkali metal hydroxide or an alkali metal carbonate. Preferably, the alkali metal is potassium or sodium.

3. The synthetic method according to claim 1, wherein The polyoxyethylene sorbitan fatty acid ester is at least one selected from the group consisting of Tween 20, Tween 40, Tween 60, Tween 80 and Tween 85.

4. The synthetic method according to claim 1, wherein The fatty acid is a C8 to C18 fatty acid. For example, the fatty acid is at least one selected from the group consisting of C8 fatty acids, C9 fatty acids, C10 fatty acids, C11 fatty acids, C12 fatty acids, C13 fatty acids, C14 fatty acids, C15 fatty acids, C16 fatty acids, C17 fatty acids, and C18 fatty acids.

5. The synthetic method according to claim 1, wherein The degree of polymerization n of the polyglycerol is 2 to 10. For example, the polyglycerol is at least one selected from the group consisting of diglycerol, triglycerol, tetraglycerol, pentaglycerol, hexaglycerol, heptaglycerol, octaglycerol, nonaglycerol, and decaglycerol.

6. The synthetic method according to claim 1, wherein The weight ratio of component A to component B is 0.01-100, preferably 0.02-50, more preferably 0.05-20, and most preferably 0.1-10.

7. The synthetic method according to claim 1, wherein Based on the total weight of the esterification raw materials composed of fatty acids and polyglycerol, component A accounts for 0.05-0.8% of the total weight of the esterification raw materials.

8. The synthetic method according to claim 5, wherein The molar ratio of the amount of fatty acid to the amount of polyglycerol added is 1 to (n+2).

9. The synthetic method according to claim 1, wherein The reaction temperature is 100-230°C.

10. The synthesis method according to claim 1, wherein The reaction time is 1 to 10 hours.