KR20000014664A - Recrystallizing method of sucrose fatty acid ester - Google Patents

Abstract

PURPOSE: A recrystallizing method of sucrose fatty acid ester using the adequate selection of an organic solvent and the recrystallizing condition is provided which can manufacture sucrose fatty acid ester possible to be pulverized simply in high yield without passing through the conventional spray-drying process and crushing process. CONSTITUTION: A process is disclosed for recrystallizing sucrose fatty acid ester manufactured by the reaction of sugar with high-grade fatty acid ester containing C8-C22 using a mixture solvent of aromatic hydrocarbon and ketone in high purity and yield. The recrystallizing mixture solvent uses 1-10 times the amount of sucrose fatty acid ester to be recrystallized in a weight ratio. The recrystallizing mixture solvent is C3-C6 ketone such as acetone, methylethylketone, methylisopropylketone, and methylisobutylketone and C6-C8 aromatic hydrocarbon such as benzene, toluene, ethylbenzene, and xylene. The recrystallizing method has a melting temperature of 50-100°C and a recrystallizing temperature of -10 to ordinary temperatures.

Description

Recrystallization method of sucrose fatty acid ester

The present invention relates to a method for recrystallization of sucrose fatty acid ester in powder form having a wide range of HLB (Hydrophile Lipophile Balance).

Sucrose Fatty Acid Ester (SFE) is generally used to prepare sugars and C ₈ to C ₂₂ higher fatty acid methyl esters with solvents such as polar solvents such as dimethylformamide (DMF) or dimethyl sulfoxide (DMSO). Process prepared in the presence of alkaline catalyst (Japanese Patent No. 35-13102), microemulsion method using water or propylene glycol as solvent (Japanese Patent No. 51-14485), solventless method without solvent The manufacturing method is known.

At present, commercially established technology is a process using a solvent. When water is used as a solvent, this process is not applied due to the failure of a stable production process, that is, a reproducible manufacturing process, and in the case of propylene glycol, Propylene glycol fatty acid esters have a fatal disadvantage that it is difficult to obtain pure SFE.

In the case of the solvent-free method, research on the purity of the reaction due to high reaction temperature, long reaction time, and partial caramelization of the product is inevitable, and the manufacturing process is not established. Is not established. In addition, studies are being conducted to synthesize SFE using enzymes, but details are not well known.

SFE is an environmentally friendly surfactant that has excellent surface activity, satisfactory biodegradability, high stability, does not destroy cell membranes, and can produce products with various HLBs. It is expected to expand its use in the market and is currently used as additives such as food, cosmetics, and pharmaceuticals, food cleaners, polymers, and feed additives.

In addition, it is also utilized in the field of polymerization, oxidation, etc. in the chemical industry, especially when used as an emulsifier during the superabsorbent polymer emulsion polymerization yields a product with little residual monomer is obtained. In addition to increasing income, a variety of products are being launched. If non-toxic SFE is used as a dispersant in the oral care field, which is a growing market, this will be one big market. In this growing field, development of various derivatives having various HLBs is required.

For example, in the field of pharmaceuticals, there is a demand for SFE having a special chemical structure and high purity, while in the general chemical industry, there is a demand for lowering costs and providing derivatives rather than purity. In line with this trend, development of high value-added products and competitive process development are required.

Accordingly, the present invention provides a recrystallization method that can be produced in a high yield of sucrose fatty acid ester that can be easily powdered without the conventional spray drying process, grinding process, etc. by utilizing the appropriate selection of organic solvents and recrystallization conditions, etc. The purpose is.

Unlike commonly used food emulsifiers such as propylene glycol fatty acid esters, glycerin fatty acid esters, and sorbitan fatty acid esters, SFE is capable of producing a wide range of HLB by controlling the molar ratio of sugar and fatty acid methyl esters. It is characteristic.

In the present invention, a water washing process is performed to remove impurities in the product. The crude SFE after this process is obtained through a recrystallization method by controlling the ratio of a mixed solvent of toluene / methylethyl ketone to obtain high purity SFE in powder form in high yield. It is a big feature that it can produce a competitive product by establishing a suitable process.

Another is that the color of the product is slightly improved in the water washing process, but by recrystallization, the color of the product becomes more white (especially coffee whiteners, skin moisturizers for cosmetics, etc.). The result is a more pure substance that results in a higher value for the product.

Specifically, when describing the SFE manufacturing method, the sugar used for the production of SFE is required to have a purity of 99.5% or more, 0.1% or less per inversion, and 500 ppm or less of moisture. A high content of invert sugar (sugar, which is a disaccharide, is broken down into glucose and fructose by hydrolysis; this mixture is called invert sugar) results in coloration of the product, which is undesirable due to the reaction of the invert sugar with fatty acid methyl esters. It is preferable not to use it because a substance is produced. The amount of sugar used is about 0.1 to 20 moles, preferably about 0.2 to 8 moles, based on the molar amount of fatty acid methyl ester used.

The fatty acid methyl esters used in the reaction include C ₈ to C ₂₂ higher saturated fatty acids and unsaturated fatty acids, which are prepared from natural palm oil or tallow fatty acids, which are commonly used as industrial raw materials for sucrose fatty acid esters. For example, saturation of caproic acid (C ₈ ), capric acid (C ₁₀ ), lauryl acid (C ₁₂ ), myristic acid (C ₁₄ ), palmitic acid (C ₁₆ ), stearic acid (C ₁₈ ), and the like And methyl esters of unsaturated fatty acids such as oleic acid (C _{18: 1} ), linoleic acid (C _{18: 2} ), and linolenic acid (C _{18: 3} ).

In particular, long-chain and saturated fatty acids are used in the emulsification of foods. In the case of short or medium chains, the bitter taste of the product is impossible. Because there is a characteristic. In addition, it is common to use saturated fatty acid having excellent oxidation stability. Laurinic acid is used a lot as a washing | cleaning agent. The fatty acid methyl esters used may be mixed and used depending on the required physical properties.

As a solvent, DMSO is used for thermal stability, solubility in sugar, and safety for the environment. The solvent is used in a weight ratio of 20 to 200% based on the total solid content of sugar and fatty acids. The reaction is carried out in the presence of an alkali catalyst, but the acidic substance also catalyzes, but its capacity is weaker than that of alkali, and in the case of SFE, since sugar is decomposed by acid, it cannot be used.

Alkaline catalysts do not have very good solubility in dimethyl sulfoxide (DMSO), and the reaction proceeds in a completely dissolved state because of the relatively high use of solvents in the manufacture of high HLB. Examples include alkali metal hydrides, alkali metal hydroxides, alkalis and metal carbonates, and potassium carbonate and sodium carbonate are most effective. The amount of these to be used is preferably 0.001 to 0.1 equivalents based on fatty acid methyl ester. The reaction temperature is generally 50 to 150 ° C, preferably 70 to 120 ° C. When the reaction proceeds, the methanol generated as the reaction proceeds must be effectively removed to complete the reaction within the desired time. This requires some vacuum, which depends on the reaction temperature, but is usually controlled between 10 and 200 Torr.

In addition, the sugar has eight hydroxy groups, so that the composition of the mixture of mono to octasubstituents can be controlled by reaction with the fatty acid methyl ester, which is controlled by the molar ratio of the starting sugar and fatty acid methyl ester. After completion of the reaction, the same amount of organic acid is injected to remove the activity of the catalyst present in the reaction solution. Sulfuric acid and the like are added to the reaction mixture of SFE and neutralized in the form of metal salt to stabilize the product.

It should be noted that if the neutralization reaction is not carried out immediately after the end of the reaction, a product whose composition is different from the target product will be obtained.

The neutralizing agents used in the present invention may be used by mixing with each other. Neutralization was completed by stirring for about 1 to 2 hours, DMSO used as a reaction solvent for desugaring was removed to 50 to 100% of the amount of the first solvent used in vacuo, and then a desugaring process was performed.

Then, the filtrate separated through the filtration process is subjected to continuous concentration and washing process, the crude SFE is filtered under pressure to make a wet cake and recrystallized using a mixed solvent of aromatic hydrocarbon / ketone. SFE can be obtained with high yield.

Examples of the recrystallized solvent used in the present invention include C ₃ to C ₆ ketones such as acetone, methyl ethyl ketone, methyl isopropyl ketone and methyl isobutyl ketone, and C ₆ to C ₈ aromatics such as benzene, toluene, ethyl benzene and xylene Hydrocarbon. If the amount of the recrystallization solvent to be used is too large, the recrystallization to the desired shape is preferably 1 to 10 times of the SFE sample to be recrystallized, and is dissolved at 50 to 100 ℃ by cooling the temperature to -10 ℃ to room temperature to powder You can get the product in the form. Here, when the temperature is out of the range, a difference in yield may occur.

The recrystallization solvent to be used can be powdered only by the recrystallization method, and the complete removal of the solvent in a short time during drying is also expected to shorten the process time.

With the proper choice of recrystallization solvents, powder products can be produced by simple recrystallization method without the complicated process that must go through to make high-purity SFE powder product. It can raise and have the effect of the invention of securing a competitive process.

Hereinafter, the present invention will be described in more detail with reference to Examples.

Example

Example 1

Dissolve 220g of sugar in 700g of DMSO and add 65g of methylstearate to it. 1.5 g of potassium carbonate was added to the mixture, the temperature was raised to 90 ° C., and the reaction was completed in 4 hours while distilling the methanol produced under reduced pressure. DMSO solution of succinic acid (4.4 g as succinic acid) was immediately added to the reaction solution to complete neutralization, and concentrated to 50% solids concentration under reduced pressure.

500g of isobutanol / toluene (5: 5, weight ratio) was added dropwise for 30 minutes while maintaining 80 ℃ for desugaring. After completely dissolving SFE, cooling to 15 ℃ was carried out to desugar and filtered. To remove isobutanol in the crude SFE obtained through the separation process such as washing process, toluene was injected three times as much as the product and completely removed through azeotropic distillation.

Next, take 30g of crude SFE product, inject 90g of methyl ethyl ketone / toluene (1.3: 1.7 weight ratio) mixed solvent, melt at 60 ℃, recrystallize at 0 ℃, and analyze the dried product by GPC. It was confirmed that the ratio of the powder product of the desired composition, namely mono-: di-: tri-, which did not need a separate process, had a value of 70: 25: 5 (HLB 15), and the recrystallization yield was 95% (28.5 g).

Example 2

Recrystallized under the same conditions as in Example 1 but recrystallized by adjusting the weight ratio of the mixed solvent to 1.0: 2.0 (methylethylketone / toluene) in order to reduce the costly use of methyl ethyl ketone. It was confirmed that the yield was obtained in 96% (28.8 g) yield.

Example 3

Recrystallized under the same conditions as in Example 2, but the weight of the mixed solvent used to reduce the amount of expensive methyl ethyl ketone was reduced to 2.5 times (75 g) compared to the product, resulting in 97% of the same product as in Example 1. (29.1 g) was obtained in the yield.

Comparative Example 1

When recrystallized using methyl ethyl ketone alone as a recrystallization solvent under the same conditions as in Example 1, but methyl ethyl ketone was used as the recrystallization solvent, the composition of the product was changed and the product was not a powder, but a crystalline form (fine appearance of salt or sugar). ), The grinding process is required, and the effect to be obtained in the present invention cannot be seen.

Comparative Example 2

Recrystallization was carried out under the same conditions as in Example 1, but recrystallization was performed using toluene as a recrystallization solvent. Recrystallization at 0 ° C. using 120 g of a recrystallized solvent confirmed that the product was not recrystallized, but had a viscous entanglement in a viscous paste state, which was not suitable as a recrystallized solvent.

Example 4

376.2 g of sugar is dissolved in 1530 g of DMSO, and 298 g of methylstearate is added thereto and mixed (target product HLB 9). 6.91 g of potassium carbonate was added to the mixture, and the temperature was raised to 90 ° C., and the reaction was completed in 4 hours and 30 minutes while distilling under reduced pressure. An acetic acid DMSO solution (6.05 g as acetic acid) was immediately added to the reaction solution to complete neutralization, and concentrated to 50% solids concentration under reduced pressure. While maintaining 80 ° C. for desugaring, 1,000 g of the mixed solvent for desugaring in Example 1 was added dropwise in 30 minutes to completely dissolve the SFE, and then cooled to 15 ° C. to carry out desugaring. Take 30g of crude SFE obtained through 90g of methyl ethyl ketone / toluene (1.0: 1.0 weight ratio) mixed solvent, melt at 60 ℃, recrystallize at 0 ℃, and analyze the dried product by GPC. In other words, a mono-: di-: tri- ratio of 50.1: 29.7: 18.2 (HLB 9) was obtained in high yield (95.6%, 28.7g), and the fatty acid methyl ester was about 2.0%.

In order to manufacture high purity SFE in powder form, the product can be commercialized only after spray drying and drying and grinding, whereas in the present invention, the composition of the product does not change by using a solubility difference in the solvent of the product. Since the product is manufactured through a simple drying process, it is possible to establish a competitive process such as cost savings due to equipment costs and solvent recovery. Conventional recrystallization method using alcohols, ketones, the composition of the product is changed and the alcohol has a disadvantage of requiring a long drying time in order to reach the emulsifier specifications for food due to the affinity with the product, while in the present invention The recrystallized solvent system used has the advantage that this problem can be solved simply.

Claims (5)

Sucrose fatty acid ester produced by the reaction of sugar and higher fatty acid esters having carbons of C8 to C22 is prepared using a mixed solvent of aromatic hydrocarbon / ketones in the form of powdered sucrose fatty acid ester in high purity and high yield. Recrystallization method of sucrose fatty acid ester. The method of claim 1, wherein the recrystallization solvent mixture are acetone, methyl ethyl ketone, methyl isopropyl ketone, methyl isobutyl ketone, and the like C, such as ketones and benzene, toluene, ethylbenzene, xylene, of between ₃ and C ₆ of the C ₆ to C _A method of recrystallization of sucrose fatty acid ester, characterized in that it is an aromatic hydrocarbon between _eight . The recrystallization method of sucrose fatty acid ester according to claim 1, wherein the melting temperature for recrystallization is performed between 50 ° C and 100 ° C. The recrystallization method of sucrose fatty acid ester according to claim 1, wherein the recrystallization temperature is performed between −10 ° C. and room temperature. The recrystallization method of sucrose fatty acid ester according to claim 1, wherein the recrystallized mixed solvent is used in an amount of 1 to 10 times the weight ratio of sucrose fatty acid ester to be recrystallized.