JPH02123192A - Purification of fatty acid - Google Patents

Abstract

PURPOSE:To obtain a fatty acid having excellent color tone and storage stability, etc., and suitable as an industrial raw material for esters, amides, etc., or a raw material for soap or surfactant by adding a specific amount of an organic peroxide to a fatty acid and distilling the mixture optionally after heating. CONSTITUTION:(A) A natural fatty acid derived from animal or vegetable oil and fat, fish oil, etc., a synthetic fatty acid or their hydrogenated product is added with (B) 0.01-3wt.% of an organic peroxide such as di-t-butyl peroxide or lauroyl peroxide and the mixture is distilled optionally after heating. The inert heavy substances (polymers) of colored, color-developing and odorous oxygen-containing impurities such as carbonyl compound, hydroxy compound, epoxy compound and phenolic compound are removed as distillation residue.

Description

[Detailed Description of the Invention] [Industrial Application Field] Fatty acids derived from animal and vegetable oils, fish oils, etc. are important as various esters, amides, etc., as industrial raw materials, or as raw materials for soaps and various surfactants. .

The present invention relates to a method for refining fatty acids to obtain fatty acids with excellent hue, storage stability, etc. in producing these fatty acids, which are important as raw materials for various raw materials.

[Prior art and problems to be solved by the invention] Commonly used fatty acid purification methods include adsorption methods using activated clay and activated carbon, as well as polycarboxylic acid (West German Patent No. 20
38468), boric acid (U.S. Pat. No. 2,862,943), sulfuric acid (U.S. Pat. No. 3,489,779), boron trifluoride (U.S. Pat. No. 2,583,028), amine compounds (
U.S. Patent No. 3471536), combination of organic amines and phenolic compounds (Japanese Patent Publication No. 7408/1986, Japanese Patent Publication No. 53-7408,
4-9166), and the combined use of a phenolic compound and a boric acid compound (Japanese Patent Publication No. 63-23180).

However, with conventional techniques, although some of the colored substances contained in fatty acids are removed, it is not possible to obtain fatty acids with a sufficiently light color.

Moreover, these treatments have the problem of deteriorating the yield.

Fatty acids derived from natural products contain unstable substances derived from natural products, which are easily changed by heating, long-term storage, etc., and cause the problem of coloring the fatty acids. Various methods have been proposed to solve this problem, but these techniques are not sufficient.

[Means to solve the problem]

The present inventors conducted intensive research to obtain a fatty acid without the drawbacks of the conventional wave 4-#j as described above, and found that after adding an organic peroxide to a fatty acid or heating it after addition, 1
The present invention was based on the discovery that a fatty acid with excellent hue, storage stability, etc. can be obtained by distilling the fatty acids.

That is, in the present invention, organic peroxide is added to the fatty acid from 0.01 to
The present invention provides a method for purifying fatty acids, which is characterized in that the fatty acids are distilled after addition of 30% weight or after addition and heating.

The fatty acids used as raw materials for purification in the present invention include natural fatty acids made from animal and vegetable oils, fish oils, etc.
Examples include synthetic fatty acids and hydrogenated fatty acids.

The organic peroxide used as a treatment agent in the present invention includes generally known organic peroxides. Specifically, for example, ketone peroxide m is replaced with J thyl ethyl ketone peroxide, methyl acetoacetyl 1-peroxide, etc.); peroxyketals (1,1-bis(t-phthyl baroxy)-3, 3,5-trimethylcyclohexane, 2,2-bis(t-butylperoxy)
octane, 1,1-bis(t-butylperoxy)cyclohexane, 2,2-bis(L-butylperoxy)butane, etc.); hydroperoxides ([-butylhydroboroxyside, 2.5 -dimethylhexane-2,
5-cybidrobar oxide, l,L3,3-tetramethylbutyl hydroperoxide, etc.); dialkyl peroxides (di-t-butyl peroxide, 2
, 5 dimethyl-2,5-di(t-phthylbaroxy)hexane, etc.) diacyl peroxides (acetyl peroxide, isobutyryl peroxide, octanoyl peroxide, decanoyl peroxide, lauroyl peroxide, 3.3 5-1-listylhexanoyl peroxide, etc.); peroxydicarbonates (isopropyl peroxydicarbonate, di-
2-ethylhexyl peroxycarbonate, di-n--
Propyl peroxydicarbonate, cimilistyl peroxycarbonate, di-2-ethoxyethyl peroxycarbonate, dimethoxyisopropyl peroxycarbonate, di(3-methyl-3-methoxybutyl) peroxycarbonate, di-allyl peroxycarbonate oxydicarbonate, etc.); peroxyesters (L-butylperoxyacetate, t-butylperoxyisobutyrate,
L-butylperoxylaurate, t-butylperoxyneodecanoate, t-butylperoxy-2-ethyl-\xanoate, t-butylperoxy-' 3
+5+5-trimethylhexanoate, t-butylperoxylaurate, L-butylperoxyisopropyl carbonate, etc.).

The processing conditions for the organic peroxide are such that the organic peroxide used is sufficiently decomposed (radical generation), and reacts with the colored, colored, and odorous impurities described below to form an inert heavy substance (polymerized product).
Select the temperature and time that can change the process.

Among organic peroxides, those whose decomposition products can be easily separated from the fatty acids and which are highly safe are particularly preferred.

In the present invention, the amount of organic peroxide used is preferably 0.01 to 3% by weight based on the raw fatty acid; below this range, the effect will be poor, and if it is used more than this, the effect will not improve, and it will be costly. There is also a problem.

[Action] The action of organic peroxides is that the radicals generated by decomposition damage colored, colored, and odorous compounds such as carbonyl compounds, hydroxy compounds, epoxy compounds, and phenolic compounds contained in raw fatty acids. It is believed that the purpose of this method is to convert oxygen impurities into inert heavy substances (polymerized substances) that can be removed as distillation residues. Depending on the type of organic peroxide used in the present invention, the organic peroxide may be used as a low boiling point substance after treatment.
Some of these substances are removed by stirring, and others are removed as a distillation residue together with heavy impurities.

Therefore, either by adding organic peroxide to fatty acids and distilling them,
Alternatively, by heating after addition and then distilling, a fatty acid with excellent color and stability can be obtained.

〔Effect of the invention〕

The fatty acid purified by the method of the present invention has excellent hue stability against heat and oxidation, and also exhibits good hue stability in reactions with acids and basic agents.

〔Example〕

Next, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples.

Example 1 Pre-distilled fatty acid obtained by fractional distillation of coconut fatty acid (carbon number 6
300 g of a mixture of ~10 fatty acids) and 1.5 g of di-t-butyl peroxide (hereinafter abbreviated as DTBPO)
(0.5% by weight based on fatty acids) was placed in a 500-flask equipped with a thermometer, stirrer, and Dimroth and heated. The temperature is 1
Keep at 90"C and continue heating for 2 hours. Approximately 120"C
After cooling, acetone and L-butyl alcohol, which are decomposition products of DTBPO, are distilled off under reduced pressure. Thereafter, it was distilled under a vacuum of 30 mm Hg to a bottom temperature of 185° C. to obtain the fine coconut oil pre-distilled fatty acid of the present invention.

Example 2 3 g of coconut oil peroxide (1% by weight based on fatty acids) was added to 300 g of coconut oil pre-distilled fatty acid of Example 1, and 17
After heating at 0°C for 12 hours, it was distilled under the same conditions as in Example 1 to obtain purified coconut oil pre-distilled fatty acids. Incidentally, since the decomposed product of lauroyl peroxide is lauric acid, it can be removed as a distillation residue.

Example 3 After adding 3 g of lauroyl peroxide to 300 g of the coconut oil pre-run fatty acid of Example 1, the mixture was distilled under the same conditions as in Example 1 to obtain a refined coconut oil pre-run fatty acid.

Comparative Example 1 Coconut oil pre-distilled fatty acid 300B of Example (1) was distilled under the same conditions as in Example 1 without adding the above-mentioned organic peroxide to obtain a simple distilled coconut oil pre-distilled fatty acid.

Table 1 shows the results of comparing the yield, hue, hue stability due to base and acid, and hue stability due to heat and oxidation of purified coconut oil pre-distilled fatty acids and simple distilled coconut oil pre-distilled fatty acids according to the present invention.
Shown below.

Table 1 Note) Item ■: Hue after heating fatty acids at 205°C for 2 hours under a nitrogen stream Item ■: Hue after heating fatty acids at 100°C for 3 hours in the atmosphere ■: Equimolar amount of fatty acids Add jetanolamine,
Hue after heating at 150°C for 11 hours in the atmosphere with occasional stirring ■ 0.05% para-toluenesulfonic acid in di-fatty acids
After addition, hue after heating at 150°C for 2 hours without stirring with nitrogen gas Table 1 shows that the product according to the present invention not only has excellent hue and thermal and thermal oxidation hue stability, but also has excellent resistance to base and acid. There is also very little coloring caused by reagents.

Example 4. Comparative Example 2 Undistilled coconut oil fatty acid (neutralization value 262.2, iodine value 9
．． 8) 1.5 g of DTBPO was added to 300 g, and the same operation as in Example 1 was performed, followed by distillation to obtain purified coconut oil fatty acid (Example 4).

Further, the same coconut oil fatty acid was distilled without the above-mentioned DTBPO treatment to obtain a simple distilled coconut oil fatty acid (Comparative Example 2).

The test results for each coconut oil fatty acid obtained are shown in the table.

Table-2 Example 5. Comparative Example 3 Undistilled oleic acid (neutralization value 193.6, iodine value 91
．． 8) Add 1.5g of DTBPO to 300g and make 170
'C, After heat treatment for 2 hours, the same operation as in Example 1 was carried out and distillation was performed to obtain purified oleic acid (Example 5).

Further, the same oleic acid was distilled to obtain simple distilled oleic acid without the above-mentioned DTBPO treatment (Comparative Example 3).

The test results for each oleic acid obtained are shown in Table 3.

Table-3 Example 6. Comparative Example 4 Undistilled stearic acid (neutralization value 194.5, iodine value 1
．． 5) 1.5 g of DTBPO was added to 300 g, and the same operation as in Example 1 was performed, followed by distillation to obtain purified stearic acid (Example 6).

In addition, the same stearic acid was distilled without the above-mentioned DTBPO treatment to obtain simple distilled stearic acid (Comparative Example 4)
.

The test results of the obtained stearic acid are shown in Table 4.

Table-4

Claims (1)

[Claims] After adding 0.01 to 3% by weight of organic peroxide to fatty acids,
Alternatively, a method for refining fatty acids characterized by heating after addition and then distilling.