A composite fatty acyl amino acid salt solution and its preparation method and application

Abstract

The present invention relates to a composite fatty acyl amino acid salt solution and a preparation method and application thereof, and belongs to the technical field of surfactants. The present invention creatively uses a low eutectic solvent prepared from sodium hydroxide and polyethylene glycol of a certain molecular weight as an acyl chloride protective agent, ultrasonically blends it with the composite fatty acyl chloride at low temperature, and then drops the blended mixture into the aqueous phase obtained by neutralizing sodium hydroxide and glycine in deionized water, uses liquid alkali as a pH regulator, thereby causing a Schotten-Baumann condensation reaction, and finally obtains a composite fatty acyl amino acid salt solution after ultrafiltration and adjusting the pH with a phosphoric acid solution, which can form an amino acid type facial cleanser when it is directly compounded and added with other conventional components, which not only has high stability and good consistency, but also can greatly reduce the amount of thickener used, and can also precipitate bright pearlescent light without adding pearlescent slurry.

Description

Technical Field

[0001] The invention belongs to the technical field of surfactants, and in particular relates to a composite fatty acyl amino acid salt solution and a preparation method and application thereof. Background Art

[0002] As a commonly used facial cleansing product, facial cleansers account for an increasing share of the cosmetics market. Among them, facial cleansers can be roughly divided into soap-based facial cleansers and amino acid-based facial cleansers according to the type of surfactants. Soap-based facial cleansers use soap-based surfactants as the main active ingredient, which are strong base and weak acid salts. They are quite irritating and not gentle enough in actual use, especially for people with fragile skin, which can easily cause tightness and dryness after washing. Amino acid-based facial cleansers can well solve the irritation and mildness problems of soap-based facial cleansers. However, since they are amino acid-based surfactants, they are not as irritating as amino acid-based surfactants. Amino acid-based facial cleansers have many disadvantages that limit their actual application effects. This is because in the facial cleanser formula system with amino acid surfactants as the main active ingredient, it is usually difficult to thicken and has poor stability. For this reason, it is necessary to add two or more thickeners and suspension stabilizers to improve and enhance the consistency and stability of the system, which is not economically efficient in the long run. In addition, most of the existing amino acid-based facial cleansers do not have a pearlescent effect. If bright pearlescent effects are to be precipitated, additional pearlescent slurry needs to be added, which is also not conducive to economic benefits. Summary of the invention

[0003] In view of the problems existing in the prior art, the purpose of the present invention is to provide a composite fatty acyl amino acid salt solution and a preparation method and application thereof. The present invention creatively uses a low eutectic solvent prepared from sodium hydroxide and polyethylene glycol with a certain molecular weight as an acyl chloride protective agent, ultrasonically blends it with the composite fatty acyl chloride at low temperature, and then drops the blended mixture into an aqueous phase obtained by neutralizing sodium hydroxide and glycine in deionized water, uses liquid alkali as a pH regulator, thereby causing a Schotten-Baumann condensation reaction, and finally obtains a composite fatty acyl amino acid salt solution after ultrafiltration and pH adjustment with a phosphoric acid solution. When the composite fatty acyl amino acid salt solution is directly compounded and other conventional components are added, an amino acid type facial cleanser can be formed, which not only has high stability and good consistency, but also can greatly reduce the amount of thickener used, and can also precipitate bright pearlescent light without adding pearlescent slurry.

[0004] The purpose of the present invention can be achieved through the following technical solutions:

[0005] A method for preparing a composite fatty acylamino acid salt solution, the preparation method comprising the following steps:

[0006] Step A: cooling 25-30 parts by weight of a low eutectic solvent to 10-15° C., adding 60-70 parts by weight of a complex fatty acid chloride at a constant temperature, and then stirring the mixture at a constant temperature for 10-15 minutes in an ultrasonic wave with a power of 300-400 W, and storing the mixture at a constant temperature to obtain component A;

[0007] Step B: adding 14-22 parts by weight of sodium hydroxide and 20-26 parts by weight of glycine to 150-160 parts by weight of deionized water, and then stirring at room temperature for 1-2 hours to obtain component B;

[0008] Step C: adding component A dropwise to component B at 5-65° C. while stirring, and continuing to stir at a constant temperature for 4-5 hours after the addition is completed. During the whole process, liquid alkali is added to maintain the pH at 10-12 to obtain component C;

[0009] Step D: ultrafilter the component C, take the filtrate, and then adjust the pH to 6.8-7.2 with a phosphoric acid solution, and the preparation is completed.

[0010] As a preferred technical solution of the present invention, the deep eutectic solvent in step A is prepared by the following steps:

[0011] (1) Sodium hydroxide and polyethylene glycol in a molar ratio of 1:3-4 are stirred and mixed at 70-80° C. for 10-12 hours, and then naturally cooled to room temperature. The preparation is completed.

[0012] Furthermore, the polyethylene glycol in step (1) refers to polyethylene glycol 2000 or polyethylene glycol 4000.

[0013] As a preferred technical solution of the present invention, the composite fatty acid chloride in step A is a mixture of at least two of octanoyl chloride, decanoyl chloride, lauroyl chloride, tetradecanoyl chloride, hexadecanoyl chloride, stearyl chloride and oleoyl chloride.

[0014] As a preferred technical solution of the present invention, the dripping in step C refers to dripping at a rate of 2-3s / drop.

[0015] As a preferred technical solution of the present invention, the liquid alkali in step C refers to sodium hydroxide solution or potassium hydroxide solution; the mass fraction of the liquid alkali is 1-3%.

[0016] As a preferred technical solution of the present invention, the ultrafiltration in step D refers to ultrafiltration using an ultrafiltration membrane with a molecular weight cutoff of 1800 Daltons.

[0017] As a preferred technical solution of the present invention, the mass fraction of the phosphoric acid solution in step D is 10-20%.

[0018] A composite fatty acyl amino acid salt solution prepared by the preparation method as described above.

[0019] An application of a composite fatty acyl amino acid salt solution, wherein the composite fatty acyl amino acid salt solution is applied to an amino acid type facial cleanser.

[0020] Beneficial effects of the present invention:

[0021] (1) The present invention creatively uses a low eutectic solvent prepared from sodium hydroxide and polyethylene glycol of a certain molecular weight as an acyl chloride protective agent, and ultrasonically blends it with a complex fatty acyl chloride at low temperature, and then drops the blended mixture into an aqueous phase obtained by neutralizing sodium hydroxide and glycine in deionized water, and uses liquid alkali as a pH regulator, so that a Schotten-Baumann condensation reaction occurs. Finally, after ultrafiltration and pH adjustment with a phosphoric acid solution, a complex fatty acyl amino acid salt solution is obtained. When the complex fatty acyl amino acid salt solution is directly compounded and other conventional components are added, an amino acid type facial cleanser can be formed, which not only has high stability and good consistency, but also can greatly reduce the amount of thickener used, and can also precipitate bright pearlescent light without adding pearlescent slurry.

[0022] (2) The present invention creatively uses glycine and a complex fatty acid chloride as raw materials, and then based on the Shoton-Baumann condensation reaction, a complex fatty acyl amino acid salt solution is prepared. Two or more fatty acyl amino acid salts are used as amino acid surfactants to produce an excellent synergistic effect, and the problems of difficult thickening, low stability, and difficulty in precipitating pearlescent light in amino acid-based facial cleansers are solved together. At the same time, since the Shoton-Baumann condensation reaction of the present invention is carried out in an aqueous phase, the acyl chloride compound is easily hydrolyzed, and then a side reaction is formed to generate a soap group, which seriously affects the final technical effect. Therefore, the present invention also uses a low eutectic solvent prepared from sodium hydroxide and a certain molecular weight of polyethylene glycol as an acyl chloride protective agent, and the low eutectic solvent is fused with the complex fatty acid chloride at low temperature. Ultrasonic blending is carried out under the condition of stirring, and then the co-dropping is carried out to cause the Schotten-Bowman condensation reaction. On the one hand, although polyethylene glycol contains hydroxyl groups and will theoretically react with acyl chloride groups, its role as a hydrogen bond donor of the low eutectic solvent, the polymer with a higher molecular weight, and the blending at low temperature greatly reduce its hydroxyl activity, effectively avoiding the introduction of additional side reactions. On the other hand, during the co-dropping, the large amount of hydrogen bond network structure of the low eutectic solvent can effectively attract glycine anions, increase the contact probability between the raw material molecules, thereby promoting the Schotten-Bowman condensation reaction and inhibiting the hydrolysis of the acyl chloride. In addition, the presence of a large amount of deionized water also promotes the dissociation of the low eutectic solvent, which to a certain extent plays the role of "consuming" water molecules and further inhibiting side reactions.

[0023] (3) The present invention creatively introduces a low eutectic solvent into the Schotten-Bowman condensation reaction to protect the acyl chloride group and inhibit its hydrolysis. Sodium hydroxide is used as a hydrogen bond acceptor and polyethylene glycol is used as a hydrogen bond donor in the low eutectic solvent. On the one hand, the Schotten-Bowman condensation reaction itself is carried out in an alkaline environment, and the introduction of the hydrogen bond acceptor achieves the effect of "killing two birds with one stone". On the other hand, the hydrogen bond donor can also be removed after subsequent ultrafiltration. Finally, no impurities are introduced. DETAILED DESCRIPTION

[0024] In order to further illustrate the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation methods, structures, features and effects of the present invention are described in detail below in combination with the embodiments.

[0025] Example 1

[0026] A method for preparing a composite fatty acylamino acid salt solution, the preparation method comprising the following steps:

[0027] Step A: cooling 25 parts by weight of a low eutectic solvent to 10° C., adding 60 parts by weight of a complex fatty acid chloride at a constant temperature, and then stirring and mixing at a constant temperature for 10 minutes in an ultrasonic wave with a power of 300 W, and storing at a constant temperature to obtain component A;

[0028] Step B: adding 14 parts by weight of sodium hydroxide and 20 parts by weight of glycine to 150 parts by weight of deionized water, and then stirring at room temperature for 1 hour to obtain component B;

[0029] Step C: adding component A dropwise to component B at 5° C. while stirring, and continuing to stir at a constant temperature for 4 hours after the addition is completed. During the whole process, liquid alkali is added to maintain the pH at 10, to obtain component C;

[0030] Step D: ultrafilter the component C, take the filtrate, and then adjust the pH to 7 with a phosphoric acid solution to complete the preparation.

[0031] The deep eutectic solvent in step A is prepared by the following steps:

[0032] (1) Sodium hydroxide and polyethylene glycol 2000 in a molar ratio of 1:3 are stirred and mixed at 70° C. for 10 h, and then naturally cooled to room temperature. The preparation is completed.

[0033] The composite fatty acid chloride in step A is prepared by mixing 9% of octanoyl chloride, 5% of decanoyl chloride, 76% of lauroyl chloride and 10% of hexadecanoyl chloride by weight.

[0034] The dropwise addition in step C refers to dropwise addition at a rate of 2s / drop.

[0035] The liquid caustic soda in step C refers to a sodium hydroxide solution; the mass fraction of the liquid caustic soda is 1%.

[0036] The ultrafiltration in step D refers to ultrafiltration using an ultrafiltration membrane with a molecular weight cutoff of 1800 Daltons.

[0037] The mass fraction of the phosphoric acid solution in step D is 10%.

[0038] A composite fatty acyl amino acid salt solution prepared by the preparation method as described above.

[0039] An application of a composite fatty acyl amino acid salt solution, wherein the composite fatty acyl amino acid salt solution is applied to an amino acid type facial cleanser.

[0040] Example 2

[0041] A method for preparing a composite fatty acylamino acid salt solution, the preparation method comprising the following steps:

[0042] Step A: cooling 30 parts by weight of a low eutectic solvent to 15° C., adding 70 parts by weight of a complex fatty acid chloride at a constant temperature, and then stirring and mixing at a constant temperature for 15 minutes in an ultrasonic wave with a power of 400 W, and storing at a constant temperature to obtain component A;

[0043] Step B: adding 22 parts by weight of sodium hydroxide and 26 parts by weight of glycine to 160 parts by weight of deionized water, and then stirring at room temperature for 2 hours to obtain component B;

[0044] Step C: adding component A dropwise to component B at 65° C. while stirring, and continuing to stir at a constant temperature for 5 hours after the addition is completed. During the whole process, liquid alkali is added to maintain the pH at 12 to obtain component C;

[0045] Step D: ultrafilter the component C, take the filtrate, and then adjust the pH to 7 with a phosphoric acid solution to complete the preparation.

[0046] The deep eutectic solvent in step A is prepared by the following steps:

[0047] (1) Sodium hydroxide and polyethylene glycol 4000 in a molar ratio of 1:4 are stirred and mixed at 80° C. for 12 h, and then naturally cooled to room temperature. The preparation is completed.

[0048] The composite fatty acid chloride in step A is prepared by mixing 10% of octanoyl chloride, 75% of lauroyl chloride, 9% of hexadecanoyl chloride and 6% of tetradecanoyl chloride by weight.

[0049] The dropwise addition in step C refers to dropwise addition at a rate of 3s / drop.

[0050] The liquid caustic soda in step C refers to a sodium hydroxide solution; the mass fraction of the liquid caustic soda is 3%.

[0051] The ultrafiltration in step D refers to ultrafiltration using an ultrafiltration membrane with a molecular weight cutoff of 1800 Daltons.

[0052] The mass fraction of the phosphoric acid solution in step D is 20%.

[0053] A composite fatty acyl amino acid salt solution prepared by the preparation method as described above.

[0054] An application of a composite fatty acyl amino acid salt solution, wherein the composite fatty acyl amino acid salt solution is applied to an amino acid type facial cleanser.

[0055] Example 3

[0056] A method for preparing a composite fatty acylamino acid salt solution, the preparation method comprising the following steps:

[0057] Step A: cooling 28 parts by weight of a low eutectic solvent to 12° C., adding 65 parts by weight of a complex fatty acid chloride at a constant temperature, and then stirring and mixing at a constant temperature for 13 minutes in an ultrasonic wave with a power of 350 W, and storing at a constant temperature to obtain component A;

[0058] Step B: adding 20 parts by weight of sodium hydroxide and 24 parts by weight of glycine to 155 parts by weight of deionized water, and then stirring at room temperature for 1.5 hours to obtain component B;

[0059] Step C: adding component A dropwise to component B at 15° C. while stirring, and continuing to stir at a constant temperature for 4.5 hours after the addition is completed. During the whole process, liquid alkali is added to maintain the pH at 11, to obtain component C;

[0060] Step D: ultrafilter the component C, take the filtrate, and then adjust the pH to 7 with a phosphoric acid solution to complete the preparation.

[0061] The deep eutectic solvent in step A is prepared by the following steps:

[0062] (1) Sodium hydroxide and polyethylene glycol 2000 in a molar ratio of 1:3.5 are stirred and mixed at 75° C. for 11 h, and then naturally cooled to room temperature. The preparation is completed.

[0063] The composite fatty acid chloride in step A is prepared by mixing 8% of octanoyl chloride, 70% of lauroyl chloride, 7% of hexadecanoyl chloride and 15% of decanoyl chloride by weight.

[0064] The dropwise addition in step C refers to dropwise addition at a rate of 2.5 s / drop.

[0065] The liquid caustic soda in step C refers to a sodium hydroxide solution; the mass fraction of the liquid caustic soda is 2%.

[0066] The ultrafiltration in step D refers to ultrafiltration using an ultrafiltration membrane with a molecular weight cutoff of 1800 Daltons.

[0067] The mass fraction of the phosphoric acid solution in step D is 15%.

[0068] A composite fatty acyl amino acid salt solution prepared by the preparation method as described above.

[0069] An application of a composite fatty acyl amino acid salt solution, wherein the composite fatty acyl amino acid salt solution is applied to an amino acid type facial cleanser.

[0070] Comparative Example 1

[0071] On the basis of Example 1, component A in step A is changed to 60 parts by weight of composite fatty acid chloride, and step D is changed to ultrafiltration of component C, taking the filtrate, and then adjusting the pH to 7 with a phosphoric acid solution, and finally distilling under reduced pressure at a vacuum degree of -0.095 MPa at 30° C. (distilling under reduced pressure to a volume equal to that of the composite fatty acyl amino acid salt solution in Example 1) to remove volatiles, and the preparation is completed; the rest remains unchanged.

[0072] Comparative Example 2

[0073] Based on Example 1, ultrasound is not performed in step A, and the rest remain unchanged.

[0074] Comparative Example 3

[0075] Based on Example 1, the temperature is not lowered in step A, and the rest remain unchanged.

[0076] Comparative Example 4

[0077] On the basis of Example 1, in step (1), polyethylene glycol 2000 was replaced by polyethylene glycol 1500, and the ultrafiltration membrane with a molecular weight cutoff of 1800 Daltons was replaced by an ultrafiltration membrane with a molecular weight cutoff of 1000 Daltons, and the rest remained unchanged.

[0078] Test Example 1

[0079] Performance Test:

[0080] The composite fatty acyl amino acid salt solutions prepared in Examples 1-3 and Comparative Examples 1-4 were respectively prepared into amino acid facial cleansers. The formula of the amino acid facial cleanser is shown in Table 1, and the specific preparation method comprises the following steps: adding composite fatty acyl amino acid salt solution, cocamidopropyl betaine, sodium cocoyl methyl taurate taurate, hydroxypropyl starch phosphate, microcrystalline cellulose, glyceryl stearate, polyglyceryl-10 laurate and glycerol to deionized water, and then stirring and mixing at 80°C for 30min, cooling naturally to 65°C and then keeping the temperature constant, adding citric acid, continuing to stir and mix at the constant temperature for 5min, then adding phenoxyethanol, 1,2-hexanediol and trehalose, stirring at the constant temperature for 1h, and cooling naturally to room temperature, and the preparation is completed.

[0081] The viscosity of the amino acid facial cleanser prepared above was tested by a rotational viscometer at 25°C to see whether it exceeded 8000 mPa·s; the amino acid facial cleanser prepared above was subjected to heat resistance and cold resistance tests according to standard GB / T 29680-2013 to judge the stability, wherein the heat resistance test observed whether there was no stratification after returning to room temperature, and the cold resistance test observed whether there was no stratification, coarsening, or discoloration after returning to room temperature; and the amino acid facial cleanser prepared above was observed to see whether it had a pearlescent effect; the above test results / observation results are shown in Table 2.

[0082] Table 1. Amino acid facial cleanser formula

[0083]

[0084] Table 2. Test results / observations

[0085]

[0086] From Test Example 1, it can be seen from the comparison between Example 1 and Comparative Examples 1-4 that the composite fatty acyl amino acid salt solution prepared by the present invention not only has high stability and good consistency when applied to amino acid facial cleansers, and can greatly reduce the amount of thickener used, but also can precipitate bright pearlescent luster without adding pearlescent slurry.

[0087] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A method for preparing a composite fatty acylamino acid salt solution, characterized in that: The preparation method comprises the following steps: Step A: cooling 25-30 parts by weight of a low eutectic solvent to 10-15° C., adding 60-70 parts by weight of a complex fatty acid chloride at a constant temperature, and then stirring the mixture at a constant temperature for 10-15 minutes in an ultrasonic wave with a power of 300-400 W, and storing the mixture at a constant temperature to obtain component A; Step B: adding 14-22 parts by weight of sodium hydroxide and 20-26 parts by weight of glycine to 150-160 parts by weight of deionized water, and then stirring at room temperature for 1-2 hours to obtain component B; Step C: adding component A dropwise to component B at 5-65° C. while stirring, and continuing to stir at a constant temperature for 4-5 hours after the addition is completed. During the whole process, liquid alkali is added to maintain the pH at 10-12 to obtain component C; Step D: ultrafiltering the component C, taking the filtrate, and then adjusting the pH to 6.8-7.2 with a phosphoric acid solution, and the preparation is completed; The deep eutectic solvent in step A is prepared by the following steps: (1) Mixing sodium hydroxide and polyethylene glycol at a molar ratio of 1:3-4 at 70-80° C. for 10-12 hours and naturally cooling to room temperature to complete the preparation; The polyethylene glycol in step (1) refers to polyethylene glycol 2000 or polyethylene glycol 4000; The composite fatty acid chloride in step A is prepared by mixing at least two of octanoyl chloride, decanoyl chloride, lauroyl chloride, tetradecanoyl chloride, hexadecanoyl chloride, stearyl chloride and oleoyl chloride; The ultrafiltration in step D refers to ultrafiltration using an ultrafiltration membrane with a molecular weight cutoff of 1800 Daltons.

2. The method for preparing a composite fatty acylamino acid salt solution according to claim 1, characterized in that: The dropwise addition in step C refers to dropwise addition at a rate of 2-3 s / drop.

3. The method for preparing a composite fatty acylamino acid salt solution according to claim 1, characterized in that: The liquid caustic soda in step C refers to a sodium hydroxide solution or a potassium hydroxide solution; the mass fraction of the liquid caustic soda is 1-3%.

4. The method for preparing a composite fatty acylamino acid salt solution according to claim 1, characterized in that: The mass fraction of the phosphoric acid solution in step D is 10-20%.

5. A complex fatty acylamino acid salt solution prepared by the preparation method according to any one of claims 1 to 4.

6. An application of the composite fatty acylamino acid salt solution as claimed in claim 5, characterized in that: The composite fatty acyl amino acid salt solution is applied to amino acid type facial cleanser.

Images