JPH0688946B2 - Method for producing polyglycerin oleate - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing polyglycerin oleate.

[Conventional technology]

Polyglycerin oleate is widely used in applications such as emulsifiers and dispersants, and is usually distilled and purified by oleic acid 1
Add 2 moles or more of glycidol to moles,
Alternatively, it is produced by esterifying this oleic acid with polyglycerin, or by performing a dehydration reaction between 1 mol of this oleic acid and 2 mol or more of glycerin.

[Problems to be solved by the invention]

However, the polyglycerin oleate produced by such a conventional method has a bad color and odor, and the color and odor become strong by heating or over time, and are unsuitable for pharmaceuticals, cosmetics, foods, etc. There was a problem that was.

When the cause was investigated, it was found that the raw material oleic acid had low purity and many impurities. That is, conventional oleic acid uses distillation as the final step, but not only impurities that are within the same boiling point range as oleic acid, but also many impurities that have a little vapor pressure in the oleic acid fraction, are simply distilled. Therefore, the effect of separating impurities is insufficient. In addition, since the distillation is carried out at a high temperature, degradation of the unsaturated fatty acid due to heat, deterioration of the substrate such as polymerization and isomerization, and thermal decomposition of impurities to form a low boiling point component which is mixed in the oleic acid fraction, etc. Therefore, the quality of oleic acid deteriorates, and only colored and odorous oleic acid can be obtained. Moreover, the obtained oleic acid has a strong tendency to be further colored and smelled when heated.

Since conventional polyglycerin oleate uses oleic acid as a raw material as described above, the color and odor of the raw material itself are transferred to the product as it is, and the color and odor are increased by being heated when the ester is produced. Therefore, the obtained product is colored and odorized, and further, the color and odor become stronger with the passage of time or by heating.
There is a problem in using it in foods and the like, and the development of polyglycerin oleate having good color, odor and stability has been longed for.

[Means for solving problems]

As a result of intensive investigations by the present inventors, by using oleic acid produced by a specific method as a raw material to produce polyglycerin oleate, colorless, odorless, and stable polyglycerin oleate can be obtained. Heading The invention has been reached.

The present invention, a fatty acid mixture containing oleic acid and urea are dissolved in an organic solvent and then cooled to separate and remove the precipitated crystals, and the fatty acid mixture contained in the organic solvent solution is partially saponified and then recrystallized to form crystals. Is added to 2 mol or more of glycidol per 1 mol of oleic acid obtained by acid-decomposing the obtained crystals, or this oleic acid is esterified with polyglycerin, or this oleic acid is added. A method for producing polyglycerin oleate, which comprises performing a dehydration reaction between 1 mol and 2 mol or more of glycerin.

The oleic acid used in the present invention is (a) a fatty acid mixture containing oleic acid and urea, which are dissolved in an organic solvent and then cooled to separate and remove precipitated crystals, and (b) a fatty acid contained in an organic solvent solution. This is oleic acid obtained by partially saponifying the mixture, then recrystallizing the crystals, and (c) acid-decomposing the obtained crystals.

The step (a) is a step of removing a higher saturated fatty acid having 16 or more carbon atoms and a monounsaturated fatty acid higher than oleic acid from a fatty acid mixture containing oleic acid, and the resulting organic solvent solution inevitably contains A small amount of urea remains. When the following step (b) is carried out using this organic solvent solution, the residual urea forms an acid salt of oleic acid and an adduct in an appropriate amount to form a hard and free-flowing crystal. The crystalline state is improved to facilitate the filtration of crystals obtained by recrystallization, polyunsaturated fatty acids such as linoleic acid, monounsaturated fatty acids lower than oleic acid,
Since the lower saturated fatty acids and other impurities can be removed efficiently, highly purified and highly purified oleic acid is produced.

As the fatty acid mixture containing oleic acid used as this raw material, any one containing oleic acid can be used, and olive oil, sesame oil, rice bran oil, soybean oil, tea seed oil, camellia oil, corn oil, Fatty acids obtained by hydrolyzing oils and fats such as rapeseed oil, balm oil, peanut oil, safflower oil, beef tallow, lard, chicken oil, sheep's fat, fish oil and mixtures thereof can be used, and contain commercially available impurities. Oleic acid can also be used as a raw material. As a matter of course,
The higher the content of oleic acid, the more efficiently the highly pure oleic acid can be obtained.

As the organic solvent used in the step (a), methanol,
Lower alcohols such as ethanol, n-propanol, and isopropanol, and mixed solvents containing these as the main components are used. The amount of the organic solvent used cannot be determined unconditionally depending on the composition of the raw material fatty acid, the target purity and yield, the setting of the number of crystallizations, etc., but is preferably 0.5 to 10 times the weight of the raw material fatty acid. If it is less than 0.5 times by weight, the separation effect will be lowered, and if it is more than 10 times by weight, the fatty acid concentration will be low and the production efficiency will be lowered, which is disadvantageous.

The amount of urea used depends on the composition of the raw material fatty acid, the target purity and yield, the crystallization temperature, the amount of solvent, etc., but the saturated fatty acid having 16 or more carbon atoms and oleic acid contained in the raw material fatty acid. It is preferably 3 to 50 times by weight of the total amount of the higher monounsaturated fatty acids. If it is less than 3 times by weight, the removal of saturated fatty acids having 16 or more carbon atoms and monounsaturated fatty acids higher than oleic acid will be insufficient, and if more than 50 times by weight, the oleic acid yield will decrease.

In the step (a), a fatty acid mixture containing urea and oleic acid is added to an organic solvent and dissolved by heating, and then gradually cooled,
It is usually 30 ° C or lower, preferably 20 to -20 ° C. Saturated fatty acids having 16 or more carbon atoms, monounsaturated fatty acids higher than oleic acid, and the like form adducts with urea and are crystallized. Therefore, these crystals are removed by usual means such as filtration and centrifugation.

Normally, (a) step is sufficient for one operation, but carbon number
It may be repeated if the separation of 16 or more saturated fatty acids or monounsaturated fatty acids higher than oleic acid is insufficient.

In the step (b), first, lithium, sodium, potassium, and an organic solvent solution of the fatty acid mixture obtained in the step (a) are added.
Add a basic compound such as hydroxide or carbonate such as ammonia to partially neutralize. Oleic acid forms an acid salt by this partial saponification, and when cooled, the acid salt of oleic acid and a small amount of urea remaining in the step (a) form an adduct appropriately and become a crystal that is easily filtered as a whole,
It is easy to separate removed components such as polyunsaturated fatty acids.
The neutralization rate in this case is from 20% of the oleic acid contained to 60% of the total fatty acid mixture, preferably 30% of the oleic acid.
% To 55% of the total fatty acid mixture. If the neutralization rate is less than 20% of oleic acid, the yield of oleic acid obtained is low, and if it exceeds 60% of the total fatty acid mixture, the separation effect decreases and the crystalline state of the crystallized oleic acid acid salt deteriorates. It is difficult to filter and the purity of the obtained oleic acid decreases.

The temperature for cooling to crystallize the acid salt of oleic acid is 10 to -30 ° C, preferably 5 to -20 ° C. If it is higher than 10 ° C, the yield of oleic acid is lowered, and if it is lower than -30 ° C, the purity of oleic acid is lowered.

The crystals of the acid salt of oleic acid thus formed are separated from the solution containing the polyunsaturated fatty acid by a conventional method.

The crystal of the acid salt of oleic acid can be further improved in purity by repeating recrystallization.

As the solvent used for repeating the recrystallization of the acid salt of oleic acid, methanol, ethanol, isopropanol,
A polar solvent such as n-butanol, isobutanol, acetone, methyl ethyl ketone, diethyl ether, ethyl acetate or acetonitrile, or a mixed solvent containing these is used. In this case, the concentration of the acid salt of oleic acid is 10-
50% by weight, and the cooling temperature is preferably 5 to -20 ° C.

The step (c) is a step of adding an acid to an acid salt of oleic acid to cause acid decomposition to obtain oleic acid.

As the acid used for acid decomposition, sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, phosphorous acid, hypophosphorous acid, carbonic acid, inorganic acids such as boric acid, acetic acid, oxalic acid, malonic acid, succinic acid, ring acid,
Organic acids such as tartaric acid and citric acid can be used. The amount of the acid used is equal to or more than the equivalent of the base forming the acid salt of oleic acid, and preferably 1.2 equivalent or more.

After acid decomposition, the acid used for acid decomposition remaining in oleic acid is removed by washing with water. When a small amount of polybasic acid such as oxalic acid or citric acid is added during the water washing, emulsification during the water washing can be prevented, and acid decomposition of the acid salt of oleic acid is also completely carried out.

In this way, high-purity oleic acid can be obtained, but in order to remove a trace amount of impurities, it is also possible to carry out an adsorbent treatment or distillation which is usually used for refining fatty acids.

As the adsorbent used for the adsorbent treatment, clay, activated clay,
Activated carbon, silica gel, alumina, silica-alumina, ion exchange resins, synthetic adsorbents and the like are available, and they are used alone or as a mixture. Although the amount of the adsorbent used varies depending on the degree of purification of oleic acid and the target quality, it is 0.1 to 5% by weight relative to oleic acid. The temperature of the adsorbent treatment is not less than the melting point of oleic acid, preferably 30 to 80 ° C. The processing time is about 20 minutes to 2 hours.

Distillation is performed under reduced pressure in an atmosphere of an inert gas under the conditions usually used for distillation of oleic acid. The vacuum should be as low as possible and the distillation temperature should be as low as possible.

The oleic acid thus obtained is of high purity and has no color or odor, and the color or odor does not become strong by heating or over time. In the present invention, this oleic acid is used as a raw material to produce polyglycerin oleate by an addition reaction, an esterification reaction or a dehydration reaction.
It does not have a strong odor, is highly pure, has no color and odor,
A product which does not change in color or odor upon heating or over time is obtained.

The polyglycerin oleate is produced by an addition reaction by adding 2 moles or more of glycidol in the presence of a Lewis acid catalyst or an alkali catalyst to 1 mole of oleic acid produced by the above method, or a tertiary amine or a quaternary amine. It can be produced by a method of adding 1 mol of glycidol to 1 mol of oleic acid using an ammonium salt as a catalyst, and then adding 1 mol or more of glycidol using a Lewis acid catalyst. In the production by the esterification reaction, the above oleic acid and polyglycerin are esterified in the presence of an acid catalyst. In the production by dehydration reaction, polyglycerol oleate is produced by dehydration reaction of 1 mol of oleic acid and 2 mol or more of glycerin in the presence or absence of these catalysts.

Examples of the Lewis acid catalyst include boron trifluoride, aluminum chloride, tin tetrachloride, antimony pentachloride and the like.
Examples of the alkaline catalyst include lithium, sodium,
There are hydroxides such as potassium and alkoxides such as methoxide and ethoxide. Examples of acid catalysts include paratoluene sulfonic acid and sulfuric acid.

As the tertiary amine used as a catalyst, triethylamine, tripropylamine, tributylamine, triisoamylamine, triethanolamine, pyridine, N-methylpiperidine, N-ethylpiperidine, N, N'-dimethylpiperazine, N, N ' -Diethylpiperazine etc.,
Examples of the quaternary ammonium salt include tetramethylammonium halide, tetraethylammonium halide, tetrapropylammonium halide, tetrabutylammonium halide, methyltriethylammonium halide, methyltripropylammonium halide, methyltributylammonium halide, ethyltrimethylammonium halide and ethyltripropyl. Ammonium halide, ethyltributylammonium halide, trimethylbenzylammonium halide, triethylbenzylammonium halide, tripropylbenzylammonium halide, tributylbenzylammonium halide, N-methylpyridinium halide, N-ethylpyridinium halide, N-propylpyridinium halide, N-dodecylpyridi There are um halides, N-hexadecylpyridinium halides, N-benzylpyridinium halides, etc., where the halides are chloride, bromide, iodide, etc., and tertiary amines or quaternary ammonium salts effective as catalysts for the addition reaction of epoxy compounds. Is used.

As the production conditions, when a Lewis acid catalyst is used in the addition reaction, 10 to 70 ° C., 10 kg / cm ² (gauge pressure, the same applies below), an alkali catalyst, a tertiary amine, and a quaternary ammonium salt catalyst are used. , 70 to 160 ° C., 10 kg / cm ² or less, 70 to 250 ° C. is suitable in the case of esterification reaction and dehydration reaction, and may be performed under reduced pressure in the case of esterification reaction and dehydration reaction. A solvent such as toluene, xylene or dimethylformamide may be used.

In any case, the amount of the catalyst used is not limited, but it is 0.001 to 5% by weight, preferably 0.01 to 1% by weight, based on the total charged amount. Particularly when it is desired to obtain polyglycerin oleate having a high monoester content, it is preferable to add glycidol using a tertiary amine or quaternary ammonium salt catalyst and then a Lewis acid catalyst.

In the present invention, the production method of the raw material oleic acid is limited, when using oleic acid by other production methods,
This is because coloring and odor are remarkable, and the color and odor become stronger by heating or with time.

〔The invention's effect〕

According to the present invention, polyglycerin oleate is produced by using oleic acid produced by a specific method. Glycerin oleate can be obtained.

〔Example〕

 Hereinafter, examples and comparative examples of the present invention will be described.

Example 1 12.42 kg of urea was added to 40 kg of methanol and dissolved by heating.
10 kg of distilled fatty acid of oleic safflower oil heated to ℃ was added and dissolved. Then, the mixture was cooled to 10 ° C. with stirring, and the resulting crystals were centrifugally filtered to obtain 52.12 kg of a filtrate (fatty acid content 6.52 kg, acid value 198.5, urea content 2.32 kg). 415g of sodium hydroxide in this filtrate (45% equivalent of fatty acid content)
5.76 kg of an aqueous solution containing the above was added and dissolved, and the mixture was cooled to -7 ° C. with stirring and separated by filtration, followed by oleic acid acid salt crystals 4.
27 kg (acid salt content 3.7 kg) was obtained. Phosphoric acid 930 on this crystal
18.56 kg of an aqueous solution containing g (1.5 times equivalent of acidic salt) was added,
It was heated and acid-decomposed. The resulting oil layer was thoroughly washed with a 0.5 wt% citric acid aqueous solution, and then dehydrated to give oleic acid 3.
Got 56 kg.

282 g (1 mol) of oleic acid obtained was added with 3 g of potassium hydroxide.
Was added, and the mixture was heated to 120 ° C. to replace nitrogen gas. Next, glycidol 320 under 110-130 ℃, 5kg / cm ² or less
g (4.3 mol) was reacted in 5 hours. After unreacted glycidol was distilled off, the mixture was cooled to 70 ° C. and neutralized with phosphoric acid. 12
It was heated to 0 ° C., dehydrated at 110 to 130 ° C. at 10 mmHg or less, and the produced salt was filtered off to obtain 550 g of polyglycerin (4 mol) monooleate.

Comparative Example 1 282 g (1 mol) of distilled oleic acid commercially available as oleic acid
Glycidol was added in the same manner as in Example 1 to give 54
0 g of polyglycerin (4 mol) monooleate was obtained.

The polyglycerin obtained from Example 1 and Comparative Example 1 (4
The following performance evaluations were performed for mol) monooleate. The results are shown in Table 1.

Color, odor and peroxide value immediately after production.

Take 150 g of sample in a 300 ml beaker and place at 100 ° C for 24 hours.
Color, odor and peroxide value after heating for hours.

After taking 150 g of a sample in a 300 ml sample bottle, sealing it and leaving it in a 50 ° C incubator for 3 months, the color, odor,
Peroxide value.

Example 2 To 564 g (2 mol) of oleic acid obtained in Example 1 was added 2 g of tetramethylammonium chloride as a catalyst, and the mixture was heated to 90 ° C. and replaced with nitrogen gas. Next, 80-100 ° C, 5kg
Under conditions of not more than / cm ² , 148 g (2 mol) of glycidol was reacted for 8 hours. After aging for 1 hour, unreacted glycidol was distilled off. The mixture was cooled to 60 ° C., the mixture was dissolved in 1 hexane, water 1 at 60 ° C. was added and the mixture was washed with water, and the separated aqueous layer was separated and removed. After washing with water three times in the same way, 10
It was dehydrated at 0 to 120 ° C. at 10 mmHg or less for 2 hours to obtain 660 g of glycerin monooleate. 6.8 g of tin tetrachloride was added to 356 g (1 mol) of the obtained glycerin monooleate, and the mixture was heated to 30 ° C. to replace nitrogen gas. 400 g (5.4 mol) of glycidol was added for 10 hours under the conditions of 30 to 50 ° C. and 5 kg / cm ² or less. After aging for 1 hour, unreacted glycidol was distilled off. 70% after neutralization with 10% by weight sodium hydroxide
Heated to ℃, dehydrated at 70 ~ 90 ℃, 2mmHg or less for 3 hours, filtered off the produced salt, 690g of polyglycerin (6mol)
I got monooleate.

Comparative Example 2 564 g (2 mol) of distilled oleic acid commercially available as oleic acid
Was carried out in the same manner as in Example 2 to obtain 680 g of polyglycerin (6 mol) monooleate.

The polyglycerin (6 obtained in Example 2 and Comparative Example 2
For mol) monooleate, the same performance evaluation as in Example 1 was performed. The result is shown in the second.

Example 3 856 g (3 mol) of oleic acid obtained in Example 1, 240 g (1 mol) of triglycerin, and 3.5 g of paratoluenesulfonic acid were added to 12
It heated at 0 degreeC and nitrogen gas substitution was performed. The esterification reaction was carried out at 120 to 140 ° C and 10 mmHg or less under a nitrogen gas stream for 14 hours. Cool to 80 ℃, neutralize with 10% by weight sodium hydroxide solution, then heat to 100 ℃, 100-110 ℃, 10mmH
After dehydration under 2 g for 2 hours, the produced salt was filtered off to obtain 995 g of triglycerin trioleate.

Comparative Example 3 856 g (3 mol) of distilled oleic acid commercially available as oleic acid
Was performed in the same manner as in Example 3 to obtain 970 g of triglycerin trioleate.

With respect to the triglycerin trioleate obtained in Example 3 and Comparative Example 3, the same performance evaluation as in Example 1 was performed. The results are shown in Table 3.

From the above results, it can be seen that the polyglycerin oleate produced by the production method of the present invention has good color and odor and is stable over time even when heated.

Claims (3)

[Claims] 1. A fatty acid mixture containing oleic acid and urea are dissolved in an organic solvent and then cooled to separate and remove the precipitated crystals. The fatty acid mixture contained in the organic solvent solution is partially saponified and then recrystallized. Crystals are separated and 2 mol or more of glycidol is added to 1 mol of oleic acid obtained by acid-decomposing the obtained crystal, or this oleic acid is esterified with polyglycerin, or this oleic acid is added. A method for producing polyglycerin oleate, which comprises performing a dehydration reaction between 1 mol of an acid and 2 mol or more of glycerin. 2. A fatty acid mixture comprising olive oil, rubber oil, rice bran oil, soybean oil, tea seed oil, camellia oil, corn oil, rapeseed oil, palm oil, peanut oil, safflower oil, beef tallow, lard,
The method according to claim 1, which is a fatty acid obtained by hydrolyzing chicken oil, sheep fat, or fish oil, a mixture thereof, or oleic acid containing impurities. 3. The process according to claim 1, wherein the partial saponification neutralizes 20% of oleic acid contained in the fatty acid mixture to 60% of the total fatty acid mixture.