JPH0711285A - Method for purifying vegetable wax - Google Patents

Abstract

PURPOSE:To purify the subject wax useful for foods, etc., by melting crude wax extracted from a plant, reacting the melted crude wax with a specific metal compound, adding a polar solvent thereto and carrying out deacidification and decoloring in simple operation reduced in load of cost. CONSTITUTION:(A) Crude wax extracted from a plant is melted and a fatty acid isolated from the component A is made to react with (B) a divalent metal compound and (C) a polar solvent is added to the reactional product and the mixture is heated to 75-100 deg.C and the wax component is extracted with the component C to purify the objective wax. Furthermore, as the component A, either one of carnauba wax, candelilla wax, rice wax and sugarcane wax is preferably used and as the component B, an oxide or a carbonate of an alkaline earth metal is preferably used and as the component C, a lower alcohol is preferably used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for refining a crude wax extracted from plants, and relates to a method for removing resin components and free fatty acids in a crude vegetable wax to improve the quality of the wax.

[0002]

2. Description of the Related Art As waxes extracted from plants, there are carnauba wax, candelilla wax, rice bran wax, sugarken wax and the like, and purification treatments such as decolorization and deodorization have been performed for commercialization. Since these are natural products, they contain a large amount of esters, hydrocarbons, free long-chain fatty acids, free long-chain alcohols, and resin components. Among them, the long-chain fatty acid and the resin component have different physical behaviors from other components and cause various problems in expanding the range of application of such wax, so it is necessary to remove them. There is no industrially-known example of purification treatment that changes the composition of components.

For example, carnauba wax is Copernicia
cerifera Martius is a plant wax obtained from the leaves of a plant of the family Palmaceae, has a high melting point of about 80 to 86 ° C, contains a hydroxyl acid ester, and has excellent emulsifying properties. Therefore, it has many uses such as cosmetics, polishes, carbon inks, leather finishing, precision casting, pharmaceuticals, polishes and paints. Usually, carnauba wax has a different composition depending on the part of the palm leaf to be obtained, and the so-called No. 1 wax contains an ester content of 80 to 85%, and other components include free alcohol and fatty acid and about 3 to 4 % Resin content. However, as the quality of the wax decreases, the ester content decreases and the color tone also deteriorates.

In particular, the resin content of No. 2 wax and No. 3 wax increases to about 20 to 40%, and there are problems such as clogging during handling and poor solubility in ethanol. Japanese Patent Laid-Open Publication No. 9-34242 discusses the removal method. Further, the free fatty acid causes a phenomenon of bleeding on the surface of the wax (bleeding), which causes quality deterioration of various products and deterioration of commercial value in appearance. This bleeding occurs remarkably when the acid value of the wax is about 10 or more. Conventionally, as a deoxidizing method for solid fats, an esterification method (JP-A-2-115300)
Also known is a method of making alkaline soap in an organic solvent and washing with water. For example, rice bran wax is obtained by cooling and depositing rice bran oil, and the deoxidation of rice bran wax is also performed at the same time by alkaline deoxidizing a hexane solution of crude rice bran oil.

[0005]

However, although the above-mentioned esterification method is convenient as an operation method, it is difficult to use it for food use because it is a synthetic product. Further, although an organic acid is used for preventing coloration, it tends to be colored by heating, which causes a problem in terms of color tone. Further, in the method of washing with alkaline soap and rinsing with water, the solution is emulsified in an actual operation and it is difficult to separate the soap from the wax. Therefore, an object of the present invention is to provide a method that is simple in operation and simultaneously performs deoxidation of crude wax extracted from plants, improvement of color tone, and removal of resin components without causing quality deterioration due to coloring. is there.

[0006]

In order to solve the above-mentioned problems, the present inventors have earnestly studied, and as a result, after reacting a free fatty acid in a crude wax extracted from a plant with a divalent metal compound. It was found that the metal soap produced can be efficiently deoxidized by removing it together with the resin component using a polar solvent, and also has a decolorizing effect.

That is, according to the present invention, a crude wax extracted from a plant is melted, a divalent metal compound is allowed to act on the free fatty acid in the wax, and a polar solvent is added to the wax to add 75 to the free fatty acid.
It is a method for purifying a vegetable wax, which comprises heating to -100 ° C and extracting the wax component with a polar solvent. Monovalent metal soap such as sodium soap has good solubility in a polar solvent and is not suitable for separation from wax. Further, metal soaps having a valence of 3 or more, such as aluminum soaps, are not suitable because they gelate the polar solvent. Alkaline earth metals are preferable as the divalent metal, and calcium and / or magnesium are particularly preferable. That is, in order to produce a metallic soap, vegetable wax is melted, calcium and / or
Alternatively, a metal powder of magnesium, an oxide, a hydroxide, a carbonate or the like is allowed to act. These may be used alone or as a mixture. Oxides and carbonates are particularly preferable. The addition amount is appropriately 1 to 20 times the theoretical amount calculated from the acid value of the plant wax to be treated. Further, in order to promote the soaping reaction, coexistence of water, dibasic acid, hydrogen peroxide, surfactant, polyhydric alcohol, aluminosilicate, alkali metal ion and the like is effective.

In addition, the free fatty acid in the vegetable wax is once neutralized with an alkali metal hydroxide such as sodium and then reacted with an alkaline earth metal chloride or sulfate in an aqueous solution to obtain the desired metal. There is a way to get soap.
In the case of this method, in order to increase the solubility of the wax in the polar solvent, it is necessary to sufficiently dehydrate the reaction liquid before the extraction operation. Next, a polar solvent is added to the vegetable wax containing the divalent metal soap obtained by the above operation, and the temperature is 75 ° C to 100 ° C.
To dissolve the wax. At this time, the insoluble resin component and the divalent metal soap are deposited as a paste-like precipitate, and the excess unreacted metal or unreacted metal compound is precipitated as a solid at the bottom of the solvent. After the precipitate and the supernatant liquid are allowed to stand still and separated while being heated to such a temperature, a supernatant liquid is obtained by an operation such as decantation, and the solvent is further removed by distillation, crystallization, filtration treatment or the like. The purified vegetable wax of The purified vegetable wax thus obtained is decolorized as well as being reduced in acid value. Examples of the polar solvent used in the present invention include lower alcohols such as methanol, ethanol, butanol, propanol, and isopropanol, and acetone and methyl ethyl ketone. Ethanol or isopropanol is preferable from the viewpoint of boiling point and solubility. Examples are shown below, but these do not limit the embodiments of the present invention.

[0009]

【Example】

Example 1 8 g of Carnauba Wax No. 3 product having an acid value of 15
Thaw at 0 ° C. Add 1g of magnesium oxide,
The mixture was stirred under reduced pressure at 80 ° C. for 30 minutes. 100 ml of ethanol was added to this and refluxed for 30 minutes. After standing at 75 ° C. for a further 15 minutes, the precipitate was removed by decantation, and the supernatant was concentrated by distilling off ethanol. This ethanol treatment was repeated 3 times to obtain 13 g of the desired purified carnauba wax. The purified wax had an acid value of 7, and was decolorized compared to the raw material. See also TLC
As a result of (thin layer chromatography) analysis, the resin content was minute.

Example 2 80 g of No. 1 carnauba wax having an acid value of 3
Thaw at ℃. 0.5 g of magnesium oxide and 0.05 g of sodium carbonate were added, and the mixture was stirred under reduced pressure at 80 ° C. for 30 minutes. 100 ml of ethanol was added to this and refluxed for 30 minutes. After standing at 75 ° C. for a further 15 minutes, the precipitate was removed by decantation, and the supernatant was concentrated by distilling off ethanol. This ethanol treatment was performed 3 times to obtain 17 g of the desired purified carnauba wax. The purified wax had an acid value of 1, and was decolorized compared to the raw material. As a result of TLC analysis, no spot corresponding to the resin component was detected.

Example 3 80 g of crude rice bran wax having an acid value of 15
Thaw at ℃. 1 g of calcium oxide was added, and the mixture was stirred under reduced pressure at 80 ° C. for 30 minutes. 100 ml of ethanol was added to this and refluxed for 30 minutes. 7 more minutes
After standing at 5 ° C, the precipitate was removed by decantation,
The supernatant was concentrated by distilling off ethanol. This ethanol treatment was performed 3 times to obtain 13 g of the desired purified rice bran wax. The purified wax had an acid value of 9, and was decolorized compared to the raw material. No TLC spot corresponding to the resin component was detected.

Example 4 The filter cake obtained in the sugar refining process using sugar cane as a raw material was dried and extracted with hexane at 68 ° C. to obtain a crude wax having an acid value of 15. This crude wax 20
After melting g at 80 ° C., an aqueous sodium hydroxide solution (0.21 g / 10 ml) was added, and the mixture was stirred at 80 ° C.
After 2 minutes, 1 g of calcium chloride was added, and the mixture was further stirred for 15 minutes at 90 ° C. Then, after dehydration under reduced pressure at 80 ° C., 200 ml of ethanol was added and refluxed for 30 minutes. After standing at 75 ° C. for a further 15 minutes, the precipitate was removed by decantation, the supernatant was cooled, and the generated crystals were filtered off. This was desolvated at 100 ° C. to obtain 8 g of a purified wax. The purified wax had an acid value of 3, and was decolorized as compared with the raw wax.

[0013]

According to the present invention, a crude vegetable wax is used.
It is possible to decolorize at the same time as deoxidation and efficiently remove the resin component by a simple and low-cost operation. Further, since the additive whose safety has been confirmed is used, the purified wax obtained in the present invention can be used in various fields including foods, cosmetics, pharmaceuticals, etc. without anxiety.

Claims (4)

[Claims] 1. A crude wax extracted from a plant is melted, a divalent metal compound is allowed to act on the free fatty acid in the wax, and a polar solvent is added thereto and heated to 75 to 100 ° C. to remove the wax component. A method for purifying a vegetable wax, which comprises extracting with the polar solvent. 2. The refining method according to claim 1, wherein the crude wax extracted from the plant is any one selected from carnauba wax, candelilla wax, rice wax and sugarken wax. 3. The purification method according to claim 1, wherein the divalent metal compound is an oxide or carbonate of an alkaline earth metal. 4. The purification method according to claim 1, wherein the polar solvent is a lower alcohol.