JPH0641439B2 - Process for producing polyoxyalkylene polyhydric alcohol oleate - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing a polyoxyalkylene polyhydric alcohol oleate.

[Conventional technology]

Polyoxyalkylene polyhydric alcohol oleate is widely used for applications such as emulsifiers, solubilizers, and dispersants. Usually, polyoxyalkylene polyhydric alcohol oleate is produced by adding alkylene oxide to polyhydric alcohol oleate in the presence of a catalyst and removing the catalyst.

However, since the conventional polyoxyalkylene polyhydric alcohol oleate uses oleic acid which has not been sufficiently purified as a raw material, it is colored and has a bad odor. In addition, the degree of coloring and odor increased by heating or simply leaving it unsuitable for use in medicines, cosmetics and the like.
Further, conventional oleic acid uses distillation as a purification step.However, not only impurities having the same boiling point range as oleic acid but also many impurities having a vapor pressure to some extent can be obtained by simple distillation. Since it is entrained in the particles, the effect of separating impurities is insufficient. Further, since the distillation is carried out at a high temperature, decomposition of unsaturated fatty acids due to heat, deterioration of quality such as polymerization, isomerization and the like, and low-boiling point components due to thermal decomposition of impurities are mixed in the oleic acid fraction. As a result, the quality of oleic acid deteriorates, and only colored and odorous oleic acid can be obtained. Moreover, when the obtained oleic acid was heated, the degree of coloring and odor tended to further increase.

[Problems to be solved by the invention]

The conventional polyoxyalkylene polyhydric alcohol oleate uses oleic acid as a raw material as described above, and is heated when an ester is produced and an alkylene oxide is added. Further, coloring or odor is further intensified with heating or with the passage of time, and there is a problem in using it for pharmaceuticals, cosmetics, etc., and there is a strong demand for the development of colorless and odorless polyoxyalkylene polyhydric alcohol oleate. It was

[Means for solving problems]

As a result of intensive studies by the present inventors, by adding an alkylene oxide to a partial ester of high-purity oleic acid and a polyhydric alcohol produced by a specific method, colorless,
The present invention has been completed by finding that an odorless and stable polyoxyalkylene polyhydric alcohol oleate can be obtained. That is, after dissolving a fatty acid mixture containing oleic acid and urea in an organic solvent, the crystals precipitated by cooling are separated and removed, and the fatty acid mixture contained in the organic solvent solution is partially saponified and then crystallized by recrystallization. Of oleic acid produced by acid-decomposing the obtained crystals with a polyhydric alcohol to produce a partial ester, and the partial ester is a single alkylene oxide having 2 to 18 carbon atoms. A method for producing a polyoxyalkylene polyhydric alcohol oleate, which comprises adding a substance or a mixture thereof.

The method for producing oleic acid used in the present invention will be described in detail below.

(A) The fatty acid mixture containing oleic acid and urea were dissolved in an organic solvent and then cooled to separate and remove the precipitated crystals, and (b) the fatty acid mixture contained in the organic solvent solution was partially saponified and then recrystallized. This is a method for producing oleic acid, in which crystals are separated by crystallization and the obtained crystals are acid-decomposed.

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

The fatty acid mixture containing oleic acid used as a raw material can be used if it contains oleic acid, olive oil, sesame oil, rice bran oil, soybean oil, tea seed oil,
Camellia oil, corn oil, rapeseed oil, palm oil, peanut oil,
Fatty acids obtained by hydrolyzing fats and oils such as safflower oil, beef tallow, lard, chicken oil, sheep fat, fish oil and the like can be used, and oleic acid containing commercially available impurities 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), lower alcohols such as methanol, 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 unconditionally specified 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 it is 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, dissolved by heating, and then gradually cooled, usually at 30 ° C or lower, preferably in the range of 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 the number of carbon atoms is 1
This step may be repeated if the separation of 6 or more saturated fatty acids or monounsaturated fatty acids higher than oleic acid is insufficient.

In the step (b), first, the organic solvent solution of the fatty acid mixture obtained in the step (b) is partially added with a basic compound such as hydroxide, carbonate, etc. of lithium, sodium, potassium, etc. or ammonia, etc. Saponify. Oleic acid forms an acidic salt by this partial saponification, and when cooled, the acidic salt of oleic acid and a small amount of urea remaining in the step (a) form an appropriate adduct and become crystals that are easy to filter as a whole, It is easy to separate components to be removed such as polyunsaturated fatty acids.
The saponification rate in this case is 20% of the contained oleic acid.
To 60% of the total fatty acid mixture, preferably 30% of oleic acid to 55% of the total fatty acid mixture. When the saponification rate is less than 20% of oleic acid, the yield of oleic acid obtained is low, and when it exceeds 60% of the total fatty acid mixture, the separation effect is lowered and the crystalline state of the crystallized acid salt of oleic acid is deteriorated. 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. 1
If the temperature is higher than 0 ° C, the yield of oleic acid will decrease, and if it is lower than -30 ° C, the purity of oleic acid will decrease.

The produced crystals of the acidic salt of oleic acid can be separated from a solution containing a polyunsaturated fatty acid and the like by a usual method.

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

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

In the step (c), an acid is added to an acid salt of oleic acid to decompose the acid,
This is a step of obtaining 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, malic acid,
Organic acids such as tartaric acid and citric acid can be used. The amount of the acid used is at least equivalent to the base forming the acid salt of oleic acid, and preferably at least 1.2 times equivalent.

After acid decomposition, the acid 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 washing with water, emulsification at the time of washing with water can be prevented, and acid decomposition of the acid salt of oleic acid can be 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. A vacuum degree as high as possible and a distillation temperature as low as possible are preferable.

Examples of the alkylene oxide having 2 to 18 carbon atoms include ethylene oxide, propylene oxide, butylene oxide,
Examples include styrene oxide, dodecene oxide, tetradecene oxide, hexadecene oxide, octadecene oxide, and tetrahydrofuran.

As the polyhydric alcohol, glycerin, diglycerin,
Polyglycerin, trimethylolethane, trimethylolpropane, 1,3,5-pentanetriol, erythritol, pentaerythritol, dipentaerythritol, sorbitol, sorbitan, condensates of sorbitol and glycerin, adonitol, arabitol, xylitol, mannitol and other polyvalents Alcohols or their partially etherified products, xylose, arabinose,
Ribose, rhamnose, glucose, fructose, galactose, mannose, sorbose, cellobiose,
Maltose, isomaltose, trehalose, sucrose, raffinose, gentianose, saccharides such as melezitose and their partially etherified compounds are mentioned, but among the hydroxyl groups of these compounds, at least one is esterified and the remaining hydroxyl groups. Of these, at least one must remain a hydroxyl group.

Examples of the catalyst for adding alkylene oxide to the partial ester of polyhydric alcohol include Lewis acid-based catalysts such as boron trifluoride ether, aluminum chloride, tin tetrachloride and antimony pentachloride, or alkali catalysts such as lithium, sodium and potassium. , Hydroxide, methoxide, ethoxide, etc. can be used, and the reaction conditions are 0 to 70 ° C. for the Lewis acid catalyst, 10 kg / cm ² G or less, and 90 to 150 ° C. for the alkali catalyst, 10 kg / cm 2. ² G or less is suitable.

In the present invention, the production method of oleic acid to be used is specified because only the polyoxyalkylene polyhydric alcohol oleate with remarkable coloring and odor can be obtained by using the other production method.

Examples of the present invention will be shown below.

[Example 1] 12.42 kg of urea was added to 40 kg of methanol and dissolved by heating.
Distilled fatty acid 1 of oleic safflower oil heated to 50 ℃
0 kg 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).
415 g of sodium hydroxide was added to this filtrate (containing fatty acid of 45 g).
5.76 kg of an aqueous solution containing (% equivalent weight) was added and dissolved, and the mixture was cooled to −7 ° C. while stirring and separated by filtration to obtain 4.27 kg of acid salt crystals of oleic acid (acid content of 3.7 kg). To this crystal was added 18.56 kg of an aqueous solution containing 930 g of phosphoric acid (1.5 equivalents of acid salt), and the mixture was heated to be acid-decomposed. 0.5% by weight of the obtained oil layer
After sufficiently washing with an aqueous citric acid solution, the product was dehydrated to obtain 3.56 kg of purified oleic acid.

To a four-necked flask equipped with a condenser and a water separator, 2220 g of this oleic acid, 1230 g of anhydrous sorbitan, 9 g of anhydrous sodium carbonate as a catalyst and 4.5 g of phosphorous acid were added.
After sufficiently substituting with nitrogen gas at 50 ° C, the temperature was raised to 230 ° C in 1 hour and 30 minutes while blowing nitrogen gas. 220-24
The esterification reaction was carried out at 0 ° C. for 5 hours. After cooling to 80 ° C, decolorize with 35% by weight hydrogen peroxide solution,
Dehydrated at less than mmHg for 3 hours, filtered off the salt formed and 2968g
Sorbitan monooleate was obtained.

2 g of potassium hydroxide was added to 440 g of the obtained sorbitan monooleate, and the mixture was heated to 120 ° C. to replace nitrogen gas. At 120 to 140 ° C. and under 5 kg / cm ² G, 920 g of ethylene oxide was added for 5 hours. After cooling to 80 ° C. and neutralizing with phosphoric acid, dehydration was carried out at 70 to 90 ° C. and 5 mmHg or less for 3 hours, and then the produced salt was filtered off to obtain 1300 g of polyoxyethylene (20 mol) sorbitan monooleate. .

The quality of the obtained polyoxyalkylene polyhydric alcohol oleate, polyoxyethylene (20 mol) sorbitan monooleate in this example, was evaluated in the following items. The results are shown in Table 1.

(1) Hydroxyl value, saponification value, peroxide value immediately after production,
Color, smell.

(2) Take 150g of sample in a 300ml beaker, 100 ℃
Hydroxyl value, saponification value, peroxide value, color and odor after heating for 24 hours.

(3) After taking 150 g of a sample in a 300 ml sample bottle, sealing it and leaving it in a thermostat at 50 ° C. for 3 months, the hydroxyl value, saponification value, peroxide value, color and odor.

In the following examples and comparative examples, quality evaluation was performed by the same method.

Comparative Example 1 2220 g of commercially available distilled oleic acid was used as oleic acid, and the reaction was carried out in the same manner as in Example 1 to obtain 1260 g of polyoxyethylene (20 mol) sorbitan monooleate.

The obtained polyoxyethylene (20 mol) sorbitan monooleate was evaluated for quality in the same manner as in Example 1, and the results are also shown in Table 1.

Example 2 Using 1704 g (6 mol) of oleic acid prepared in Example 1 and 324 g (2 mol) of sorbitan, a reaction was carried out in the same manner as in Example 1 to obtain 1750 g of sorbitan trioleate. .

2 g of potassium hydroxide as a catalyst was added to 960 g (1 mol) of the obtained sorbitan trioleate, and 240 g (5.5 mol) of ethylene oxide was reacted in the same manner as in Example 1,
Purification was performed to obtain 1150 g of polyoxyethylene (5 mol) sorbitan trioleate. The quality was evaluated and the results are shown in Table 2.

Comparative Example 2 Using commercially available distilled oleic acid as oleic acid, the reaction was carried out in the same manner as in Example 2 to obtain 1100 g of polyoxyethylene (5 mol) sorbitan trioleate. The quality was evaluated and the results are also shown in Table 2.

[Example 3] 564 g (2 mol) of oleic acid produced in Example 1, 166 g (1 mol) of diglycerin, and paratoluenesulfonic acid 2.5.
g to 120 ℃, under nitrogen gas flow, 120-140 ℃, 1
The dehydration reaction was performed at 0 mmHg or less for 7 hours. Then, 7 g of potassium hydroxide was added, and 1280 g (22 mol) of propylene oxide was added in 8 hours at 110 to 130 ° C. under 5 kg / cm ² G or less. After distilling off unreacted propylene oxide, it was cooled to 80 ° C. and neutralized with phosphoric acid.

The mixture was heated to 100 ° C., dehydrated at 100 to 120 ° C. and 10 mmHg or less for 3 hours, and the produced salt was filtered off to obtain 1860 g of polyoxypropylene (20 mol) diglycerin dioleate. The quality was evaluated and the results are shown in Table 3.

[Comparative Example 3] Using commercially available distilled oleic acid as oleic acid, the reaction was carried out in the same manner as in Example 3 to obtain 1830 g of polyoxypropylene (20 mol) diglycerin dioleate. The quality was evaluated and the results are also shown in Table 3.

[Example 4] 282 g (1 mol) of oleic acid and 240 g (1 mol) of triglycerin produced in Example 1 were reacted under the same conditions as in Example 3 using 1.5 g of paratoluenesulfonic acid as a catalyst. Glycerin monooleate was obtained. Then 5g
600 g (10.5 mol) of propylene oxide and 730 g (16.5 mol) of ethylene oxide were reacted under the same conditions as in Example 3 to obtain 1790 g of polyoxyethylene (16 mol) and polyoxypropylene (10 mol). Triglycerin monooleate was obtained. The quality was evaluated and the results are shown in Table 4.

[Comparative Example 4] Using commercially available distilled oleic acid as oleic acid, the reaction was carried out in the same manner as in Example 4 to obtain 1760 g of polyoxyethylene (16 mol) and polyoxypropylene (10 mol).
Triglycerin monooleate was obtained. The quality was evaluated and the results are also shown in Table 4.

〔The invention's effect〕

According to the present invention, a polyhydric alcohol partial oleic acid ester starting from high-purity oleic acid produced by a specific method, produced by a method of adding alkylene oxide,
A polyoxyalkylene polyhydric alcohol oleate that is free from coloration and odor and that is stable even when heated or for a long time is obtained.

Claims (1)

[Claims] 1. A fatty acid mixture containing oleic acid and urea are dissolved in an organic solvent, and the mixture is 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 by crystals, the obtained crystals are esterified with oleic acid and polyhydric alcohol produced by acid decomposition to produce a partial ester,
A method for producing a polyoxyalkylene polyhydric alcohol oleate, which comprises adding a single alkylene oxide having 2 to 18 carbon atoms or a mixture thereof to the partial ester.