JPH0466464B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a method for producing polyglycerin having a good hue, a high content of dimers or tetramers, and a small amount of cyclic products. It can be safely used as a food emulsifier base or a cosmetic base. [Prior Art] Conventionally, methods for producing polyglycerin are broadly classified into the following three methods. (1) Condensation of glycerin A method of condensing glycerin by heating it to 220-280°C in a nitrogen or carbon dioxide atmosphere in the presence of an alkali catalyst. (2) Recovery of glycerin from distillation residue A method in which the residue produced when natural or synthetic glycerin is distilled is extracted using an organic solvent such as alcohol or dioxane. (3) Epichlorohydrin method A method of manufacturing by adding a concentrated aqueous sodium hydroxide solution to epichlorohydrin and condensing it. In all of these methods, the product is colored dark brown due to side reactions, produces an unpleasant odor, and contains a large amount of cyclic polyglycerin in addition to linear polyglycerin. Therefore, in order to make it into a product, it must be further subjected to steam deodorization, activated carbon treatment,
Requires purification processes such as activated clay treatment and ion exchange resin treatment. Furthermore, a method has been proposed in which an alkali catalyst and a reducing agent (metallic aluminum or metallic magnesium) are added during condensation of glycerin to produce polyglycerin with a good hue. The. Journal.
of. J. American. oil. Chemistry. Society (JAOCS) Vol. 58, p. 878 (1981) [Problems to be solved by the invention] In the polyglycerin obtained by these conventional methods, in addition to chain polyglycerin, cyclic polyglycerin is formed during the condensation process. Produces polyglycerin. Cyclic polyglycerin is questionable in terms of safety for humans.
This poses a problem when producing polyglycerol fatty acid esters or polyglycerol ricinoleic acid esters as food additives. In reality, the hydroxyl value of polyglycerin is smaller than the theoretical value because
This is caused by cyclization due to intramolecular ester condensation. Additionally, FAO FOOD AND NUTRITION
PAPER 4 (Food and Agriculture Organization of the United Nations, published in 1978), pages 270-271, states that the sum of diglycerin, triglycerin, and tetraglycerin in the polyglycerin portion is 75% by weight or more regarding polyglycerin fatty acid esters as food additives. In addition, the content of high molecular weight polyglycerin higher than heptaglycerin is specified to be 10% or less. However, according to the conventional method, diglyline,
If an attempt is made to increase the content of triglycerin or tetraglycerin, that is, dimers or tetramers, the content of unreacted glycerin will also increase, which requires time and effort to remove unreacted substances by operations such as distillation.
Also, if you try to reduce the content of unreacted substances,
When the amount of high molecular weight polyglycerin greater than heptaglycerin exceeds 10% by weight, the amount of cyclic polyglycerin also increases and the hue further deteriorates. [Means for Solving the Problems] The present invention solves the above problems, and is characterized in that an alkali catalyst and an aluminum oxide adsorbent are added to glycerin and condensed therein. That is, according to the present invention, in which an aluminum oxide adsorbent is used in the condensation reaction of glycerin in the presence of an alkaline catalyst, the color is good, the content of dimers to tetramers is high, the amount of cyclic polyglycerin is low, and food additives can be obtained. It is possible to produce polyglycerin that can be safely used as a raw material. In the present invention, the alkali catalyst used for condensation includes potassium carbonate, sodium carbonate, lithium carbonate, potassium hydroxide, sodium hydroxide, lithium hydroxide, sodium hydrogen carbonate, sodium methylate, calcium oxide, magnesium oxide, calcium carbonate, Magnesium carbonate, zinc oxide, etc. can be used. Among these, alkali metal carbonates such as potassium carbonate, sodium carbonate, and lithium tricarbonate are particularly preferred because they are powdery and non-hygroscopic. There is no particular limit to the amount added; glycerin
The amount is 0.1 to 5 parts by weight, preferably 0.5 to 2.5 parts by weight per 100 parts by weight. Aluminum oxide-based adsorbents may be aluminum oxide itself, such as activated alumina and aluminum oxide reagents, but adsorbents containing aluminum oxide, such as activated clay, zeolite, and synthetic adsorbents (for example, Kyowa Chemical Co., Ltd. Co., Ltd., trade name: KYOWARD), etc. are also used, and in this case, the content of the aluminum oxide component is required to be 5% by weight or more. The amount added is not particularly limited, but is usually 0.1 to 5 parts by weight, preferably 0.5 to 2.5 parts by weight, per 100 parts by weight of glycerin. The condensation reaction is carried out under the usual conditions for glycerin condensation reaction in the presence of an alkali catalyst. For example, after heating glycerin in a nitrogen or carbon dioxide atmosphere and removing moisture at 100 to 200°C, an alkali catalyst and an aluminum oxide adsorbent are added,
Raise the temperature to ~260°C and react for 3 to 10 hours. [Function] In the present invention, the aluminum oxide adsorbent used together with the alkaline catalyst has a catalytic effect as a solid acid in addition to its decolorizing effect during the reaction, and is effective in controlling the degree of polymerization and suppressing cyclization. It is thought that it exerts an effective effect. [Effects of the Invention] According to the present invention, the hue is good and the dimer to quaternary
Polyglycerin having a high molecular weight content of heptaglycerin or higher molecular weight polyglycerin of 10% by weight or less and a low content of cyclic bodies can be obtained. Therefore, the polyglycerin according to the present invention relates to a fatty acid ester of polyglycerin.
It meets FAO standards and can be safely used as a raw material for food additives. [Examples] In the following examples, parts and percentages are parts by weight and percentages by weight, respectively. 100 parts of glycerin was placed in a four-necked flask equipped with a stirrer, and heated with a mantle heater while blowing nitrogen gas into the glycerin. The amount of nitrogen gas blown was 2 ml/min.g glycerin.
After raising the temperature to 150°C, it was kept at this temperature for 30 minutes to distill off the moisture in the glycerin. Next, an alkali catalyst and an aluminum oxide adsorbent shown in Table 1 were added, the temperature was raised to 250°C, and a condensation reaction was carried out for 5 hours. The reaction solution was cooled to 100°C, 80 parts of ion-exchanged water was added, 4 parts of powdered activated carbon was added, and the mixture was heated at 80°C.
After stirring for 30 minutes, it was filtered. The obtained decolorized polyglycerin aqueous solution was treated with H-type strongly acidic ion exchange resin PK.
-216 (manufactured by Mitsubishi Kasei Corporation) and OH-type strongly basic ion exchange resin PA-308 (manufactured by Mitsubishi Kasei Corporation) were passed through a 1:1 mixed bed column at a superficial velocity of 3 to decolorize and remove catalyst. Finally, using a thin film distiller, the vacuum level was 5 mmHg.
The target polyglycerin was obtained by dehydration at a temperature of 150°C. The results are shown in Table 1. The activated clay is V ₂ SUPER manufactured by Mizusawa Chemical Co., Ltd., aluminum oxide content 10.4%, Al ₂ O ₃ is reagent special grade, Kiyoward is Kiyoward 300, manufactured by Kyowa Chemical Co., Ltd. aluminum oxide content 26.3%, and zeolite is used. were manufactured by Mizusawa Chemical Co., Ltd., respectively. As a comparative example, reagents were prepared in the same manner as in the examples except that no aluminum oxide adsorbent was used, and the results are shown in Table 2. The hue and polyglycerin composition were analyzed by the following method. (1) Hue According to Standard Oil and Fat Analysis Test Method 2.3.1-71, dark colored samples are measured using the Gardner method, and light colored samples are measured using the Gardner method.
Measured by APHA method.

【table】

[Table] (2) Polymerization degree distribution and cyclic polyglycerin content Accurate analysis is difficult, and gas chromatography using a silicon OV-1 column after trimethylsilylation or TSK-GEL (Toyo Soda Kogyo Co., Ltd.)
High-performance liquid chromatography using a high-performance liquid chromatography system (manufactured by J.D.) cannot provide satisfactory sharp analysis. The inventors used fused gas chromatography because they found it to be the most suitable analytical method and provided accurate results. The sample used was trimethylsilylated according to a conventional method. Capillary gas chromatography was performed under the following conditions. Equipment: HEWLETT PACKERD 5710A
GAS CHROMATOGRAPH Column: Metyl Silicone 10m×0.31mmφ Fused Silica Capillary Oven temperature: 100-350℃ (heating rate 16℃/
) Detector temperature: 350℃ Injection temperature: Split (100:1) 300
°C Carrier gas: Helium 0.5ml/min Detector: FID, Hydrogen 30ml/min As an example of gas chromatography using this analysis method, the results of sample No. 4 and sample No. 10 are shown in Figures 1 and 2. .

[Brief explanation of the drawing]

FIG. 1 is a gas chromatograph of sample No. 4, polyglycerin obtained by the present invention, and FIG. 2 is a gas chromatograph of sample No. 10, polyglycerin obtained by the conventional technique. In both FIG. 1 and FIG. 2, the components corresponding to each peak number are as follows. 1... Glycerin, 2... Cyclic diglycerin,
3... Chain diglycerin, 4... Cyclic triglycerin, 5... Chain triglycerin, 6... Cyclic tetraglycerin, 7... Chain tetraglycerin,
8... Pentaglycerin, 9... Hexaglycerin, 10... Heptaglycerin, 11... Octaglycerin, 12... Nonaglycerin, 13...
Decaglycerin, 14... Undecaglycerin.

Claims (1)

[Claims] 1. A method for producing polyglycerin, which comprises adding an alkali catalyst and an aluminum oxide adsorbent to glycerin and causing condensation.