Polymers for monoglyceride synthesis

Abstract

To provide a polymer compound that allows a dehydration condensation reaction between a fatty acid and glycerol to proceed even under mild conditions.SOLUTION: The present invention provides a polymer compound represented by formula (1), where, x and y are an integer of 1 or greater independently of each other, z is an integer of 0 or greater independently of x and y, and X+ is a cation having a sulfonic acid group.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present application relates to a polymeric compound that can be used as a catalyst when synthesizing a monoglyceride from a fatty acid and glycerol, a catalyst containing this polymeric compound as an active ingredient, and a method for producing a monoglyceride using this catalyst. [Background technology]

[0002] Glycerol mono-fatty acid esters (monoglycerides) are widely used in foods, antistatic agents, lubricating oil additives, etc. Monoglycerides are obtained by dehydration condensation reaction of fatty acids and glycerol, followed by distillation of the product. Since the mutual solubility of the reactant materials, fatty acids and glycerol, is extremely low, this dehydration condensation is often carried out at high temperatures, for example, above 200°C, to increase the solubility of the reactant materials. There is a need for a catalyst that can promote the dehydration condensation reaction of fatty acids and glycerol under mild conditions. Summary of the Invention [Problem to be solved by the invention]

[0003] The present application has been made in view of the above circumstances, and has an object to provide a polymer compound that can promote a dehydration condensation reaction of fatty acids and glycerol even under mild conditions. [Means for solving the problem]

[0004] The polymer compound of the present invention is represented by the following general formula (1).

[0005] [ka]

[0006] where x and y are mutually independent integers of 1 or greater, z is an integer of 0 or greater independent of x and y, and X + is a cation having a sulfonic acid group.

[0007] The catalyst of the present application is a catalyst for synthesizing a monoglyceride by dehydration condensation from a fatty acid and glycerol, and contains the polymer compound of the present application as an active ingredient.

[0008] The method for producing a monoglyceride of the present application includes a dehydration-condensation step of obtaining a monoglyceride by dehydration-condensation of a fatty acid and glycerol in the presence of a catalyst containing the polymer compound of the present application as an active ingredient. Effect of the Invention

[0009] By using the polymer compound of the present invention, a monoglyceride can be obtained from a fatty acid and glycerol even under mild reaction conditions, for example, at a temperature of 100° C. or less. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The polymer compound according to the embodiment of the present application is represented by the following general formula (1): where x and y are each an integer of 1 or more, z is an integer of 0 or more, and is independent of x and y. + is a cation having a sulfonic acid group. The polymer compound of this embodiment is a random copolymer. The ratio (molar ratio) of y to x, y / x, can be 1 / 100 or more and 20 or less. The ratio (molar ratio) of z to x, z / x, can be 0 or more and 20 or less.

[0011] [ka]

[0012] X + may be a phosphonium cation. Examples of the phosphonium cation include the cation represented by the following chemical formula (2), where n is 3 or 4.

[0013] [ka]

[0014] X +may be an ammonium cation. Examples of the ammonium cation include the cation represented by the following chemical formula (3), where n is 3 or 4.

[0015] [ka]

[0016] The polymer compound of the present embodiment can be used as a catalyst for synthesizing monoglycerides by dehydration condensation from fatty acids and glycerol. That is, the catalyst of the present embodiment is a catalyst for synthesizing monoglycerides by dehydration condensation from fatty acids and glycerol, and contains the polymer compound of the present embodiment as an active ingredient. Examples of the fatty acid include fatty acids having 12 to 18 carbon atoms. Examples of such fatty acids include lauric acid, myristic acid, palmitic acid, oleic acid, and stearic acid. In addition, the catalyst of the present embodiment may contain additional components other than the polymer compound of the present embodiment as long as they do not interfere with the synthesis of monoglycerides.

[0017] The method for producing monoglyceride according to the embodiment of the present application includes a dehydration condensation step. In the dehydration condensation step, fatty acids and glycerol are dehydration condensed in the presence of a catalyst containing the polymer compound according to the embodiment as an active ingredient to obtain a monoglyceride. By using the catalyst according to the embodiment, fatty acids and glycerol can be dehydration condensed even under mild reaction conditions of a temperature of 40° C. or higher and 100° C. or lower. When the catalyst according to the embodiment is used, fatty acids and glycerol are dehydration condensed to obtain a monoglyceride even under reaction conditions that are not mild, for example, a temperature of 200° C.

[0018] In the method for producing monoglycerides of this embodiment, the catalyst of this embodiment acts as a heterogeneous catalyst. Therefore, for example, if the catalyst of this embodiment is fixed to a reaction tube and the raw materials fatty acid and glycerol are passed through this reaction tube, monoglycerides are discharged from the reaction tube. Furthermore, in the method for producing monoglycerides of this embodiment, the selectivity of monoglycerides is high compared to the by-product diglycerides and triglycerides. Therefore, according to the method for producing monoglycerides of this embodiment, monoglycerides can be efficiently synthesized. EXAMPLES

[0019] (Synthesis of polymer compounds) As shown in the chemical reaction formula below, azobisisobutyronitrile (AIBN) and hydrochloric acid (HCl) are used to produce 4-vinyl-N-trifluoromethylsulfonylbenzenesulfonic acid amide sodium salt (TfNS-Na), 4-(trioctylphosphonio)butanesulfonic acid (P 888 A polymer compound, Poly(ILC1), was synthesized from styrene (STY), divinylbenzene (DVB), and styrene (STY).

[0020] [ka]

[0021] Synthesis Example 1 In a glass reactor with a greaseless valve, TfNS-Na, P 888 C4S, DVB, STY, AIBN, and a mixed solvent of water:THF (volume ratio) 4:1 were added. At this time, the molar ratio of TfNS-Na:DVB:STY (x:y:z) was 1:10:0. After freeze-degassing, these were stirred at a temperature of 60°C for 3 hours. The glass reactor was cooled to room temperature, and the powder and solvent generated in the glass container were transferred to a vial, after which 1M HCl was added and stirred for 24 hours. The powder was filtered through a membrane filter and washed with pure water. Furthermore, it was dried under reduced pressure at a temperature of 80°C and a pressure of 10 Pa or less to obtain Poly(ILC1). The element ratio of Poly(ILC1) was confirmed by elemental analysis (same below).

[0022] Synthesis Example 2 Poly(ILC1) was synthesized in the same manner as in Synthesis Example 1, except that water was used as the solvent instead of the mixed solvent of water and THF.

[0023] Synthesis Example 3 Poly(ILC1) was synthesized in the same manner as in Synthesis Example 1, except that the volumetric mixing ratio of water:THF was changed to 3:2.

[0024] Synthesis Example 4 Poly(ILC1) was synthesized in the same manner as in Synthesis Example 1, except that the molar ratio of TfNS-Na:DVB:STY (x:y:z) was 1:5:5.

[0025] Synthesis Example 5 P 888 C4S is converted to 4-(trioctylammonio)butane sultone (N 888 A polymer compound Poly(ILC2) represented by the following chemical formula (4) was synthesized in the same manner as in Synthesis Example 1, except that the water:THF volume mixture ratio was changed to 3:2.

[0026] [ka]

[0027] Synthesis Example 6 P 888 A polymer compound Poly(TfNS-H) represented by the following chemical formula (5) was synthesized in the same manner as in Synthesis Example 1, except that C4S was not added and the volumetric mixing ratio of water:THF was changed to 1:4.

[0028] [ka]

[0029] (Synthesis of monoglycerides) As shown in the chemical reaction formula below, oleic acid monoglyceride (monoolein) was synthesized from oleic acid and glycerol in the presence of a catalyst. At this time, oleic acid diglyceride (diolein) and oleic acid triglyceride (triolein) were produced as by-products.

[0030] [ka]

[0031] In a vial or test tube, 2 mmol of oleic acid and 8 mmol, 16 mmol, or 24 mmol of glycerol were placed as raw materials, and a catalyst was further added so that the catalyst mass / (raw material mass+catalyst mass) was 10%. As catalysts, Poly(ILC1), Poly(ILC2), and Poly(TfNS-H) of Synthesis Examples 1 to 4, ILC1 represented by the following chemical formula (6), ILC2 represented by the following chemical formula (7), p-toluenesulfonic acid, or ion exchange resin (trade name Amberlyst-15) were used. In addition, an attempt was made to synthesize monoolein from oleic acid and glycerol without using a catalyst.

[0032] [ka]

[0033] [ka]

[0034] The vial or test tube was immersed in a water bath adjusted to 60°C or an aluminum block bath adjusted to 80°C. Oleic acid and glycerol were reacted with each other while stirring at 400 rpm for 6 hours. After the reaction was completed, the reaction solution was diluted with t-butyl alcohol or 2-propanol and filtered through a membrane filter. The filtrate was analyzed by HPLC to determine the amounts of monoolein, diolein, and triolein contained in the filtrate.

[0035] If the amount of substance of the charged oleic acid is A, the amount of substance of monoolein contained in the filtrate is B, the amount of substance of diolein contained in the filtrate is C, and the amount of substance of triolein contained in the filtrate is D, the ester yield (%) was calculated as (B+C×2+D×3) / A×100, the monoolein selectivity (%) as B / (B+C+D)×100, the diolein selectivity (%) as C / (B+C+D)×100, and the triolein selectivity (%) as D / (B+C+D)×100. The results are shown in Table 1.

[0036] [Table 1]

[0037] When ILC1, which also functions as a solvent for dissolving oleic acid and glycerol, was used as a catalyst, the ester yield was high (Experimental Example 1). On the other hand, when ILC1, which also functions as a solvent for dissolving only glycerol, was used as a catalyst, the ester yield was low (Experimental Example 2). Poly(ILC1), a heterogeneous catalyst obtained by polymerizing ILC1, also showed ester synthesis catalytic activity, similar to that of Experimental Example 1 (Experimental Example 3).

[0038] When Poly(ILC1) was used, the ester yield was higher than when p-toluenesulfonic acid, a standard homogeneous catalyst, and ion exchange resin (product name Amberlyst-15), a heterogeneous catalyst, were used (Experimental Examples 3, 4, and 5). In other words, it was found that when the polymer compound of the present application was used as a catalyst, monoolein was synthesized in high yield even under mild conditions at a temperature of 60°C. However, when no catalyst was used, no ester was synthesized (Experimental Example 6).

[0039] When THF was used as a co-solvent during catalyst synthesis, the ester yield from the obtained catalyst increased (Examples 3, 7, and 8). Observation of the catalyst using an optical microscope revealed that the particle size of the catalyst was smaller when THF was used as a co-solvent than when it was not used. This is thought to have improved the dissolution of the raw material into the catalyst phase, resulting in an increased ester yield.

[0040] Furthermore, when THF was used as a co-solvent and STY was copolymerized, the ester yield increased further (Experimental Examples 3 and 9). The copolymerization of STY reduced the crosslink density, resulting in a polymer with high flexibility, which is thought to have improved the amount of raw material dissolved in the catalyst phase compared to when it was not copolymerized, allowing the reaction to proceed more efficiently. Furthermore, not only the phosphonium cation-type polymer compound Poly(ILC1), but also the ammonium cation-type polymer compound Poly(ILC2) showed ester synthesis catalytic activity (Experimental Examples 8 and 10). In contrast, the polymer compound Poly(TfNS-H), which does not have a cation, showed almost no ester synthesis catalytic activity (Experimental Example 11).

[0041] The ester yield increased with an increase in reaction temperature (Experimental Examples 3 and 12). Even when the reaction temperature was 100°C or less, the ester yield was about 85% (Experimental Example 12). Furthermore, the ester yield increased when the amount of glycerol in the raw material, that is, the glycerol ratio (molar ratio) in the raw material, increased (Experimental Examples 3, 13, and 14). Based on Le Chatelier's principle, it is believed that the yield increased because the chemical equilibrium shifted toward ester production as the glycerol ratio increased.

Claims

1. A polymer compound represented by the following general formula (1): 【Chemistry 1】 Here, x and y are mutually independent integers of 1 or more, z is an integer of 0 or more independent of x and y, and X ＋ is represented by the following chemical formula (2). 【Chemistry 2】 Here, n is 3 or 4.

2. A polymer compound represented by the following general formula (1): 【Chemistry 1】 Here, x and y are mutually independent integers of 1 or more, z is an integer of 0 or more independent of x and y, and X ＋ is represented by the following chemical formula (3). 【Chemistry 3】 Here, n is 3 or 4.

3. A catalyst for synthesizing a monoglyceride from a fatty acid and glycerol by dehydration condensation, comprising: A catalyst comprising the polymer compound of claim 1 or 2 as an active ingredient.

4. 3. A method for producing a monoglyceride, comprising a dehydration-condensation step of obtaining a monoglyceride by dehydration-condensation of a fatty acid and glycerol in the presence of a catalyst containing the polymer compound of claim 1 or 2 as an active ingredient.

5. In claim 4, In the dehydration-condensation step, dehydration-condensation is carried out at a temperature of 40° C. or higher and 100° C. or lower.

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