A surfactant composition and a preparation method thereof

Abstract

The present invention belongs to the technical field of daily chemical materials, and discloses a surfactant composition and a preparation method thereof. The preparation method comprises the following preparation steps: adding an excessive amount of fatty acid, sulfonic acid or sulfonate monomer and a catalyst into a reactor, heating to 150-250 °C under the protection of an inert atmosphere for heat preservation reaction, and then adding polyol to continue the reaction at 150-200 °C until the fatty acid residue is less than 1%, thereby obtaining the surfactant composition. The method of the present invention directly condenses the excessive fatty acid with the sulfonate monomer to obtain a fatty acyl sulfonate surfactant, and then directly esterifies the remaining fatty acid with polyol to obtain a surfactant composition of fatty acyl sulfonate and fatty acid polyol ester. By converting the excessive fatty acid into fatty acid polyol ester, the problem of high fatty acid residue is solved, and at the same time, the product itself has excellent self-thickening characteristics.

Description

Technical Field

[0001] The present invention belongs to the technical field of daily chemical materials, and particularly relates to a surfactant composition and a preparation method thereof. Background Art

[0002] Fatty acyl sulfonate surfactant, a generalized amino acid surfactant, has low irritation to the skin and good cleaning ability, and is widely used in various high-grade shampoos, facial cleansers, shampoos and other cosmetics.

[0003] In the industry, fatty acyl sulfonate surfactants are mainly prepared by the Schotten-Baumann condensation method, that is, by condensing fatty acyl chlorides with sulfonate monomers under alkaline conditions. Zeng Ping, Chen Lan, Xie Weiyue et al. disclosed that using coconut oil acyl chloride and sodium methyl taurate as raw materials, water as a solvent, and reacting under alkaline conditions to obtain an aqueous solution of sodium coconut oil acyl methyl taurate with a content of 30% (Synthesis and properties of sodium coconut oil acyl methyl taurate [J], Chemicals for daily use, "Journal of daily chemicals science", 2009, 32(6): 34-37). However, the product obtained by the above method has a low active matter content and contains a large amount of inorganic salts, and the purity and mildness of the product are difficult to guarantee, so its application is necessarily limited.

[0004] Patent US2880219A reports that fatty acyl sulfonate surfactants are synthesized in one step from excess fatty acids and sodium methyl taurate under high-temperature conditions, with a high conversion rate. However, it is difficult to remove the excess fatty acids in the product, which affects the use of the product. To solve this problem, Patent US5434276A reports that in the presence of a catalyst, fatty acyl sulfonate surfactants are synthesized in one step from excess fatty acids and sodium methyl taurate at high temperature, and a solvent washing process is used to remove the excess fatty acids. Although high conversion rates and purities are achieved, the catalyst cannot ensure complete removal, which will inevitably affect the mildness of the product. In addition, a large amount of organic solvents are used during product purification, which will inevitably lead to an increase in cost. Patent CN114181118A discloses a synthesis process for fatty acyl taurates. Fatty acids or their esters, taurine, and a solvent are added to a reaction vessel, stirred evenly, and then a catalyst is added. The reaction is heated under stirring conditions, and the water generated during the reaction needs to be removed. After the reaction ends, the fatty acyl taurate product can be obtained. This patented technology needs to be carried out under the conditions of adding alkali and a catalyst. Polyhydric alcohols only act as solvents and do not participate in the reaction. Although a high conversion rate can be achieved, there are still problems such as difficulty in removing the catalyst and difficulty in recovering the solvent. Patent CN 106588710A discloses a method for synthesizing N-acyl-N-methyl taurates using microwave. This method uses C8-18 fatty acids and N-methyl taurates as raw materials, and directly synthesizes N-acyl-N-methyl taurates by microwave heating under solvent-free conditions, cools, slurries with 90-100% ethanol, filters, then washes with 90-100% ethanol, and dries under vacuum to obtain the pure product. This patented technology synthesizes N-acyl-N-methyl taurates under microwave conditions without solvent and without catalyst. Although a high yield can be achieved, strict requirements are imposed on the microwave conditions. Summary of the Invention

[0005] Aiming at the above-mentioned shortcomings and deficiencies of the prior art, the primary object of the present invention is to provide a preparation method for a surfactant composition. The method of the present invention uses excess fatty acids and sulfonate monomers to obtain fatty acyl sulfonate surfactants through catalytic condensation, and the remaining fatty acids are then esterified with polyhydric alcohols to obtain a surfactant composition of fatty acyl sulfonates and fatty acid polyhydric alcohol esters. By converting the excess fatty acids into fatty acid polyhydric alcohol esters, the problem of high fatty acid residue is solved, and at the same time, the product itself has excellent self-thickening properties.

[0006] Another object of the present invention is to provide a surfactant composition prepared by the above method.

[0007] The object of the present invention is achieved by the following technical solutions:

[0008] A preparation method of a surfactant composition, comprising the following preparation steps:

[0009] Add an excessive amount of fatty acid, sulfonic acid or sulfonate monomer and a catalyst into a reactor, heat up to 150 - 250 °C under the protection of an inert atmosphere for heat preservation reaction, then add a polyol and continue the reaction at 150 - 200 °C until the residual fatty acid is less than 1%, to obtain the surfactant composition.

[0010] Further, the fatty acid is a fatty acid with 6 - 22 carbon atoms, straight-chain or branched-chain, saturated or having one or more unsaturated double bonds.

[0011] More preferably, the fatty acid is oleic acid, linoleic acid, linolenic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, coconut fatty acid or a combination thereof.

[0012] Further, the sulfonic acid or sulfonate monomer is sodium methyl taurate, potassium methyl taurate, methyl taurine, sodium taurate, potassium taurate, taurine, sodium 2-hydroxyethylsulfonate, potassium 2-hydroxyethylsulfonate, 2-hydroxyethylsulfonic acid, sodium 1-hydroxyisopropylsulfonate, potassium 1-hydroxyisopropylsulfonate, 1-hydroxyisopropylsulfonic acid, sodium 3-hydroxypropylsulfonate, potassium 3-hydroxypropylsulfonate, 3-hydroxypropylsulfonic acid or a combination thereof.

[0013] Further, the catalyst is a fatty acid metal salt or a metal salt catalyst of trifluoromethanesulfonic acid; preferably zinc fatty acid, iron fatty acid, zinc trifluoromethanesulfonate or iron trifluoromethanesulfonate; more preferably zinc trifluoromethanesulfonate or iron trifluoromethanesulfonate.

[0014] Verified by the present invention, the above catalysts have high catalytic activity for the reaction of fatty acid with sulfonic acid or sulfonate monomer, and at the same time, zinc trifluoromethanesulfonate or iron trifluoromethanesulfonate also has high catalytic activity for the esterification reaction of fatty acid with polyol in the presence of fatty acid.

[0015] Further, the time of the heat preservation reaction is 2 - 12 h.

[0016] More preferably, the temperature of the heat preservation reaction is 160 - 240 °C and the time is 4 - 10 h; even more preferably, the temperature of the heat preservation reaction is 180 - 220 °C and the time is 6 - 8 h.

[0017] Further, the time for adding the polyol and continuing the reaction is 6 - 10 h.

[0018] Further, the polyol is ethylene glycol, diethylene glycol, triethylene glycol, 1,2 - propanediol, 1,3 - propanediol, dipropylene glycol, tripropylene glycol, glycerol, diglycerol, triglycerol, polyglycerol or a combination thereof.

[0019] Furthermore, the molar ratio of the fatty acid, sulfonic acid or sulfonate monomer, and polyol is 1.2 to 10:1:0.2 to 9; preferably 1.2 to 5:1:0.2 to 4; more preferably 1.2 to 3:1:0.2 to 2.

[0020] A surfactant composition is prepared by the above method.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0022] (1) Since the surfactant composition synthesized in the present invention adopts the direct acylation process of fatty acid and sulfonic acid or sulfonate monomer, it is green and environmentally friendly, meeting the current requirements of green and sustainable development.

[0023] (2) The present invention uses an excessive amount of fatty acid to react with the sulfonic acid or sulfonate monomer, improving the conversion rate of the sulfonic acid or sulfonate monomer and reducing the content of residual sulfonic acid or sulfonate monomer. The product has high quality and good stability.

[0024] (3) By converting the excessive fatty acid into fatty acid polyol ester, the problem of high fatty acid residue is solved, and at the same time, the product itself has excellent self-thickening properties.

[0025] (4) The present invention uses a specific fatty acid metal salt or metal trifluoromethanesulfonate as a reaction catalyst. The above catalyst has good compatibility with the reaction system, does not require the use of a reaction solvent, and has high catalytic efficiency; and the metal trifluoromethanesulfonate can further catalyze the esterification reaction of the excessive fatty acid and polyol in the presence of fatty acid, and the product synthesis efficiency is high. Specific Embodiments

[0026] The present invention will be further described in detail below with reference to the embodiments, but the embodiments of the present invention are not limited thereto.

[0027] Example 1

[0028] The preparation method of a composition of sodium methyl lauroyl taurate and glyceryl laurate in this example includes the following preparation steps:

[0029] 300 g of sodium methyl taurate (40% aqueous solution) was added to a 1 L three-necked flask. After dehydration under reduced pressure at 100 °C until the solid content was above 95%, 300 g of lauric acid and 0.1% of zinc laurate based on the mass of the reaction materials were added. The temperature was raised to 200 °C under nitrogen protection to start the reaction. After reacting for 6 h, the system temperature was lowered to 180 °C and 70 g of glycerol was added, and the reaction continued for 6 h to end, obtaining 446 g of a composition of sodium lauroyl methyl taurate and glycerol laurate. The content of sodium lauroyl methyl taurate was measured to be 54.2% (242 g) by two-phase titration or HPLC, the content of glycerol laurate was measured to be 43.7% (195 g) by HPLC, and the residues of lauric acid and glycerol measured by HPLC were 0.5% and 1.2% respectively.

[0030] It was calculated that the conversion rate of sodium methyl taurate in this example was 94.9%, the conversion rate of glycerol was 93.8%, and the conversion rate of lauric acid was 94.5%.

[0031] Example 2

[0032] A preparation method of a composition of sodium methyl cocoyl taurate and diglycerol cocoate in this example includes the following preparation steps:

[0033] 300 g of sodium methyl taurate (40% aqueous solution) was added to a 1 L three-necked flask. After dehydration under reduced pressure at 100 °C until the solid content was above 95%, 515 g of coconut fatty acid and 0.1% of zinc cocoate based on the mass of the reaction materials were added. The temperature was raised to 200 °C under nitrogen protection to start the reaction. After reacting for 6 h, 124 g of diglycerol was added to the system, and the reaction continued for 6 h to end, obtaining 699 g of a composition of sodium cocoyl methyl taurate and diglycerol cocoate. The content of sodium methyl cocoyl taurate was measured to be 48.8% (341 g) by two-phase titration or HPLC, the content of diglycerol cocoate was measured to be 49.1% (344 g) by HPLC, and the residues of coconut fatty acid and glycerol measured by HPLC were 0.3% and 1.5% respectively.

[0034] It was calculated that the conversion rate of sodium methyl taurate in this example was 94.2%, the conversion rate of diglycerol was 93.8%, and the conversion rate of coconut fatty acid was 93.5%.

[0035] Example 3

[0036] A composition of sodium cocoyl isethionate and glycerol cocoate in this example and its preparation method

[0037] Add 148 g of sodium 2-hydroxyethanesulfonate (99% content), 686 g of coconut fatty acid, and 0.1% of zinc coconutate based on the mass of the reaction materials to a 1 L three-necked flask. Under nitrogen protection, heat up to 220 °C and start the reaction. After reacting for 6 h, cool down to 200 °C, add 92 g of glycerol to the system, and continue reacting for 6 h to completion, obtaining 866 g of a composition of sodium cocoyl 2-hydroxyethanesulfonate and glycerol coconutate. The content of sodium cocoyl 2-hydroxyethanesulfonate is measured to be 52.0% (450 g) by two-phase titration or HPLC, the content of glycerol coconutate is measured to be 45.0% (390 g) by HPLC, and the residues of lauric acid and glycerol are measured to be 0.8% and 1.1% respectively by HPLC.

[0038] It is calculated that the conversion rate of sodium 2-hydroxyethanesulfonate in this example is 95.7%, the conversion rate of glycerol is 93.5%, and the conversion rate of coconut fatty acid is 94.6%.

[0039] The surfactant composition obtained in the above example is used in the shower gel formulation, and the comparison results of the thickening performance of the formulation with that of the single sulfonate surfactant are shown in Table 1 below.

[0040] Table 1

[0041] Example 1 Comparative formulation 1 Example 2 Comparative formulation 2 Example 3 Comparative formulation 3 Deionized water To 100 To 100 To 100 To 100 To 100 To 100 Surfactant composition 10 10 10 Sodium methyl lauroyl taurate 10 Sodium methyl cocoyl taurate 10 Sodium cocoyl hydroxyethyl sulfonate 10 CAB 35 5 5 5 5 5 5 CMMEA 0.5 0.5 0.5 0.5 0.5 0.5 Citric acid q.s. q.s. q.s. q.s. q.s. q.s. Formulation viscosity (mPa·s, 25°C) 13500 1800 12400 1450 8700 2600

[0042] It can be seen from the results in Table 1 that the surfactant composition of the present invention exhibits significant self-thickening characteristics compared with the single fatty acyl sulfonate surfactant.

[0043] Example 4

[0044] Compared with Example 1, iron laurate catalyst is used to replace zinc laurate, and the rest is exactly the same.

[0045] It is calculated that the conversion rate of sodium methyl taurate in this example is 93.2%, the conversion rate of glycerol is 92.7%, and the conversion rate of lauric acid is 92.9%.

[0046] Example 5

[0047] Compared with Example 1, iron(III) trifluoromethanesulfonate catalyst is used to replace zinc laurate, and the rest is exactly the same.

[0048] It is calculated that the conversion rate of sodium methyl taurate in this example is 94.2%, the conversion rate of glycerol is 97.9%, and the conversion rate of lauric acid is 96.0%.

[0049] Example 6

[0050] To further study the effects of different catalysts on the synthesis of the composition, the sodium cocoyl isethionate and glyceryl cocoate composition was synthesized according to the method of Example 3, using zinc cocoate and zinc trifluoromethanesulfonate as catalysts respectively. After adding the catalysts, samples were taken every 1 h to detect the content of sodium cocoyl isethionate and calculate the conversion rate of sodium isethionate; after adding glycerol, samples were taken every 1 h to detect the content of glyceryl cocoate and calculate the conversion rate of glycerol, and the results were compared with those under the condition of no catalyst. The results are shown in Table 2 below.

[0051] Table 2

[0052]

[0053] As can be seen from the results in Table 2, zinc fatty acid has significant catalytic activity in the synthesis reaction of fatty acyl sulfonate, but has no catalytic activity in the reaction of fatty acid polyol ester. The conversion efficiency of glycerol is higher under the condition of no catalyst, because the higher concentration of fatty acid promotes the esterification reaction. Zinc trifluoromethanesulfonate has higher catalytic activity than zinc fatty acid in the synthesis reaction of fatty acyl sulfonate, and at the same time its catalytic effect on the synthesis reaction of fatty acid polyol ester is very significant, which can significantly improve the reaction efficiency.

[0054] The above embodiments are the preferred embodiments of the present invention, but the embodiments of the present invention are not limited by the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement methods and are all included in the protection scope of the present invention.

Claims

1. A method for preparing a surfactant composition, characterized in that, It includes the following preparation steps: Add an excessive amount of fatty acid, sulfonic acid or sulfonate monomer and a catalyst into a reactor, heat up to 150 - 250 °C under the protection of an inert atmosphere for heat preservation reaction, then add a polyol and continue the reaction at 150 - 200 °C until the residual fatty acid is less than 1%, to obtain a surfactant composition.

2. The preparation method of a surfactant composition according to claim 1, characterized in that, The fatty acid is oleic acid, linoleic acid, linolenic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, coconut fatty acid or a combination thereof; the sulfonic acid or sulfonate monomer is sodium methyl taurate, potassium methyl taurate, methyl taurine, sodium taurate, potassium taurate, taurine, sodium 2-hydroxyethylsulfonate, potassium 2-hydroxyethylsulfonate, 2-hydroxyethylsulfonic acid, sodium 1-hydroxyisopropylsulfonate, potassium 1-hydroxyisopropylsulfonate, 1-hydroxyisopropylsulfonic acid, sodium 3-hydroxypropylsulfonate, potassium 3-hydroxypropylsulfonate, 3-hydroxypropylsulfonic acid or a combination thereof.

3. The preparation method of a surfactant composition according to claim 1, characterized in that, The catalyst is a fatty acid metal salt or a metal salt catalyst of trifluoromethanesulfonic acid.

4. The preparation method of a surfactant composition according to claim 3, characterized in that, The catalyst is zinc trifluoromethanesulfonate or iron trifluoromethanesulfonate.

5. The preparation method of a surfactant composition according to claim 1, characterized in that, The temperature of the heat preservation reaction is 160 - 240 °C, and the time is 4 - 10 h.

6. The preparation method of a surfactant composition according to claim 1, characterized in that, The time for adding the polyol and continuing the reaction is 6 - 10 h.

7. The preparation method of a surfactant composition according to claim 1, wherein, The polyol is ethylene glycol, diethylene glycol, triethylene glycol, 1,2 - propanediol, 1,3 - propanediol, dipropylene glycol, tripropylene glycol, glycerol, diglycerol, triglycerol, polyglycerol or a combination thereof.

8. The preparation method of a surfactant composition according to claim 1, characterized in that, The molar ratio of the fatty acid, sulfonic acid or sulfonate monomer, and polyol is 1.2 - 10:1:0.2 - 9.

9. The preparation method of a surfactant composition according to claim 8, characterized in that, The molar ratio of the fatty acid, sulfonic acid or sulfonate monomer, and polyol is 1.2 - 3:1:0.2 - 2.

10. A surfactant composition, characterized in that, It is prepared by the method according to any one of claims 1 - 9.

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