JPH03200744A - Production of higher fatty acid monoglyceride - Google Patents

Abstract

PURPOSE:To obtain the title compound in high purity and in high yield by reacting higher fatty acid with glycidol by using any of sodium tertiary phosphate, potassium tertiary phosphate, sodium secondary phosphate, potassium secondary phosphate and hydrous salt thereof as a catalyst. CONSTITUTION:In reacting a higher fatty acid with glycidiol, one or more alkali metal phosphates selected from sodium tertiary phosphate, potassium tertiary phosphate, sodium secondary phosphate, potassium secondary phosphate and hydrous salt thereof are used as a catalyst to give a higher fatty acid monoglyceride. By this method, addition reaction can be carried out under low pressure. The title high-purity compound with low impurities can be obtained in high yield only by active carbon treatment. The catalyst is industrially and inexpensively obtainable, has low toxicity and readily separated and removed. The title compound is useful as an emulsifying agent of cosmetic, etc., and a humectant.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing higher fatty acid monoglycerides, which are generally widely used as emulsifiers and humectants in cosmetics and the like.

K Yonedate Nirasho Conventional methods for producing higher fatty acid monoglycerides include direct esterification of fatty acids and glycerin at high temperatures (170 to 240°C) in the presence of an acid or base catalyst or in the absence of a catalyst, or under similar conditions. A method based on transesterification of triazylglyceride and glycerin is known. In addition, as a method for selectively obtaining monoglyceride, there is a method that relies on a reaction between a fatty acid and glycidol using an alkali catalyst such as sodium hydroxide, a catalyst such as a tertiary amine or a quaternary ammonium salt, and further, The corresponding glycidyl ester is first prepared from the fatty acid salt and epichlorohydrin using a phase transfer catalyst such as a quaternary ammonium salt, and then the corresponding glycidyl ester is prepared.

A method has been proposed in which an epoxide ring is hydrolyzed under alkaline conditions to obtain the corresponding monoglyceride.

However, in the direct esterification of fatty acids and glycerin or the transesterification method of triazylglyceride and glycerin, the reaction requires a high temperature of about 170 to 240°C and a long time.
In addition to monoglycerides, considerable amounts of diglycerides and triglycerides are unavoidably produced as by-products, and in addition, there are difficult problems such as coloring and odor. Therefore, in order to industrially produce a monoglyceride of 90% or more, the reaction mixture thus synthesized had to undergo a further process of molecular distillation, which increased production costs. The method of adding glycidol using an alkaline catalyst such as sodium hydroxide, which has been proposed as a method to improve this problem, slightly improves the yield of monoglyceride, but avoids by-products such as polyglycerin. In order to obtain a highly pure monoglyceride, further purification and separation treatments were required. To solve these problems, tertiary amines such as triethylamine and quaternary ammonium halide catalysts such as tetraethylammonium chloride have been proposed, and these catalysts can produce monoglycerides with a purity of 90% or more. However, these catalysts are highly volatile and require a pressurized reaction to prevent volatilization, and the catalysts are expensive. If there is a problem with residual halogens, and if it is due to the reaction between fatty acid salts and shrimp chlorohydrin, (1) formation of fatty acid salts, (2) formation of glycidyl esters, and (3)
A complicated process had to be carried out, such as the production of monoglyceride by alkaline hydrolysis of the epoxide ring.

Therefore, an object of the present invention is to solve the conventional problems and to provide a novel method for easily producing substantially colorless and odorless higher fatty acid monoglycerides with a purity of 90% or more in high yield by an industrially advantageous method. The goal is to provide a method for

As a result of continuing research to solve these problems, the present inventors unexpectedly found that specific alkali metal salts, namely trisodium phosphate, tripotassium phosphate, and diphosphate, were used as catalysts. The inventors have found that these problems can be solved by using one or more alkali metal phosphates selected from sodium, dipotassium phosphate, and hydrated salts thereof, leading to the present invention.

That is, 1. when producing higher fatty acid monoglyceride by addition reaction of higher fatty acid and glycidol,
As a catalyst, trisodium phosphate, tripotassium phosphate,
A method for producing a higher fatty acid monoglyceride, which is characterized in that it uses one or more alkali metal phosphates selected from disodium phosphate, dipotassium phosphate, and hydrated salts thereof, the method for producing higher fatty acid monoglycerides used in the method of the present invention. are linear, branched and unsaturated fatty acids with carbon a7 or more that are liquid at room temperature, such as isohebbutanoic acid, 2-ethylhexanoic acid, isononanoic acid, isodecanoic acid, indoridecanoic acid,
Included are inmyristic acid, impalmitic acid, isostearic acid, oleic acid, inarachic acid, isotetracosanoic acid, isohexacosanoic acid, and the like. In addition, the above-mentioned alkali metal phosphates are used as the catalysts used in the method of the present invention, but these have a purity equivalent to that of industrial chemicals and can be used sufficiently, and all of them are compounds that can be easily obtained on an industrial scale. It is. The amount of catalyst used is higher fat I'l
0.005 to 0.1 mol per mol, preferably 0
．． A range of 0.01-0.05 mol is suitable. Glint~
In the addition reaction, the catalyst in the above ratio is first added to the higher fatty acid, preheated to 50 to 60°C, and vigorously stirred to thoroughly disperse the poorly soluble catalyst so as not to agglomerate it. On this occasion,
Addition of an inert solvent such as benzene, toluene, or chloroform maintains better dispersion. At the same time, nitrogen gas is blown into the liquid at a reaction temperature of 50-130°C, preferably 70-110°C, and 1.0-1.5 mol per mol of higher fatty acid, preferably 1.15-1.3 mol per mol of higher fatty acid. The zero reaction time, in which moles of glycidol are provided as candy and the reaction is continued until the higher fatty acids are almost completely extinguished, varies depending on the type and proportion of raw materials used, temperature, amount of catalyst, etc., but is usually 5 to 10 hours. In this case, if the amount of glycidol is less than the above range, the reaction will take a long time and it is difficult to expect the reaction to be completed, whereas if it is too much, side reactions are likely to occur, so the above range is suitable. In addition, if the amount of catalyst is too small, it will be difficult to react, and if it is too large, side reactions will easily occur and the yield will decrease, so the above range is appropriate. 0 If the reaction temperature is too low, there will be no substantial reaction, and if it is too high, there will be no substantial reaction. The above temperature range is appropriate because side reactions become noticeable and coloring and odor are likely to occur.After the reaction is complete, if unreacted glycidol and the above inert solvent are used from the reaction mixture, distill off the inert solvent. After washing, wash with water, or if the reaction product is in a bad condition, dissolve it in a solvent such as benzene, toluene, or chloroform and wash it in a hot oven several times in an island-like state until the washing water becomes neutral. This operation dissolves and removes the catalyst and trace amounts of impurities such as unreacted fatty acids and unreacted glycidol into the aqueous layer. After separating the water from the oil layer,
After treating with activated carbon, diatomaceous earth, silica gel, etc. as necessary, the solvent and water content are distilled off under reduced pressure, and the insoluble matter is filtered to obtain higher fatty acid monoglyceride.

Examples of the present invention are shown below, but these Examples are merely for illustrating specific examples of the present invention, and the present invention is not limited thereto. (manufactured by Nissan Chemical Industries, Ltd.) 500g (
1,76 mol), 100 g of toluene, and 5.6 g (0,026 mol) of tripotassium phosphate were placed in a TI glass reactor, and stirred vigorously while blowing nitrogen gas until the temperature reached 70°C. A mixed solution of 150 g (2.02 mol) of glycidol and 50 g of toluene was added dropwise from the dropping funnel through the well-suspended and dispersed dropping funnel over about 30 minutes.At the end of the dropping, the reactor temperature reached 85°C.0 reaction Harvesting was continued while maintaining the temperature at 85°C. Samples were taken periodically and the remaining amount of isostearic acid was monitored by gas chromatography. After 6 hours and 30 minutes, the residual amount of instearic acid is 1%.
The temperature was below, so after aging for another 30 minutes, 60℃
The mixture was cooled to a temperature of 500 mL, and then 500 ml of vodka was added and washed. Washing with water was repeated twice, water was separated, and 3 g of activated carbon was added to the reaction product, which was then treated at 85-95°C for 1 hour. Then, toluene and other volatile components containing water were distilled off under reduced pressure, and finally The volatile components were squeezed out under conditions of 3 mmHg and 130°C. Finally, the activated carbon was filtered to obtain 592 g of a substantially colorless and odorless product with a purity of 93.5% of isostearic acid monoglyceride determined by gas chromatography. (Yield 94.0%) Comparative Example 1 The reaction was continued for 9 hours under the same conditions as in Example 1 except that 3.48 g of potassium hydroxide was used instead of tripotassium phosphate as a catalyst. After carrying out the same operation as in Example 1 and removing toluene, glycidol and other volatile components, the content of isostearic acid monoglyceride in the product was 76% according to gas chromatography.Examples 2 to 4 Example 5 Using the same reactor as in Example 1 and using the same method but changing the type of catalyst, the results are shown in Table 1. Example 5: 216 g (1.5 mol) of 2-ethylhexanoic acid and 2.5 g (1.5 mol) of dipotassium phosphate. 61g (0,015 mol) in 500m
The liquid was charged in a 1-volume stainless steel reactor, nitrogen gas was blown into the liquid, heated while stirring vigorously, and kept at 70°C to fully suspend and disperse the catalyst.
28 g (1°72 mol) was added dropwise over 30 minutes, the reaction temperature was raised to 90°C, the reaction was continued at this temperature for 8 hours, and excess glycidol was distilled off under reduced pressure. After cooling to 60℃ and dissolving it in 200ml of toluene, the mixture was washed 3 times with 400ml of 7% hot boiled water. After separating the water, the reaction mixture was mixed with activated carbon of 80~9 tg.
After 2 hours of treatment at 5°C, the degree of vacuum was gradually increased.
Finally, it was kept at 3 m+*Hg and 120°C for 1 hour to remove toluene and other volatile components, and then the activated carbon was filtered out and the purity was determined to be 91.3% by gas chromatography.
Substantially colorless and odorless 2-ethylhexanoic acid was obtained. Yield was 324g. (Yield 94.8% vs. 2-ethylhexanoic acid standard) Examples 6 to 10 Using the same reaction apparatus as in Example-1, reactions were carried out in the same manner by changing the type of higher fatty acid.

The results are shown in Table-2.

You can get it at Further, the catalyst of the present invention is industrially available at low cost, has no toxicity, and is easily separated and removed. Further, under the reaction conditions of the present invention, there is no problem of corrosion, stainless steel is sufficient as the material of the equipment, and there is no need for expensive pressure-resistant equipment, and many other advantages can be obtained.

Claims (1)

[Claims] In a method for producing higher fatty acid monoglycerides by reacting higher fatty acids with glycidol, one or more alkali metals selected from trisodium phosphate, tripotassium phosphate, disodium phosphate, dipotassium phosphate and hydrated salts thereof as a catalyst. A method for producing higher fatty acid monoglyceride, characterized by using a phosphate.