阅读说明：本技术 一种保湿剂及其制备方法 (Humectant and preparation method thereof ) 是由 张静 蔺海政 张德旸 桂振友 鲍元野 于 2021-08-10 设计创作，主要内容包括：本发明公开了一种新型保湿剂及其制备方法,采用2,2-亚氨基二乙基磺酸和脂肪酸酰氯在碱性条件下制备得到了N-脂肪酸酰基二取代牛磺酸保湿剂,此保湿剂白色无味,有良好的保湿性、吸湿性,无刺激。具有调节皮肤屏障功能和防止皮肤的水分损失,增强皮肤黏合和皮肤对外界的适应能力。(The invention discloses a novel humectant and a preparation method thereof, wherein 2, 2-imino-diethyl-sulfonic acid and fatty acid chloride are adopted to prepare the N-fatty acid acyl disubstituted taurine humectant under an alkaline condition, and the humectant is white and tasteless, has good moisture retention and hygroscopicity, and is free of stimulation. Has effects in regulating skin barrier function, preventing water loss of skin, and improving skin adhesion and skin adaptability to external environment.)

1. A novel humectant is characterized in that the structural formula is as follows:

where n is 3 to 13, preferably n is an odd number of 3 to 13, more preferably an odd number of 5 to 11.

2. The method for producing a humectant according to claim 1, characterized in that: reacting 2, 2-imino diethyl sulfonic acid and fatty acid chloride under an alkaline condition to prepare a humectant;

preferably, the humectant is prepared by reacting 2, 2-imino diethyl sulfonic acid and fatty acid chloride under the action of an alkaline resin catalyst and an acetal auxiliary agent.

3. The method for producing a humectant according to claim 2, characterized in that: the structural formula of the 2, 2-imino diethyl sulfonic acid is as follows:

preferably, the concentration of the 2, 2-iminodiethylsulfonic acid aqueous solution is from 30 to 50 wt%, preferably from 35 to 48 wt%, more preferably from 40 to 45 wt%;

preferably, the fatty acid chloride is a straight-chain saturated fatty acid chloride of C6-C16, preferably a straight-chain saturated fatty acid chloride of C8, C10, C12, C14, more preferably a straight-chain saturated fatty acid chloride of C10, C12.

4. The method for producing a humectant according to claim 2 or 3, characterized in that: the molar ratio of 2, 2-iminodiethanesulfonic acid to fatty acid chloride is 1: 0.5-1: 1.5, preferably 1: 0.8-1: 1.2, more preferably 1: 0.9-1: 1.1.

5. the method for producing a humectant according to any one of claims 2 to 4, characterized in that: the basic resin catalyst is one or the mixture of more than two of strong basic styrene anion exchange resin and weak basic styrene anion exchange resin, preferably one or the mixture of more than two of 201X7 strong basic styrene anion exchange resin and D301 macroporous weak basic styrene anion exchange resin, more preferably D301 macroporous weak basic styrene anion exchange resin or the mixture of 201X7 strong basic styrene anion exchange resin and D301 macroporous weak basic styrene anion exchange resin,

preferably, the mass ratio of the strongly basic styrene anion exchange resin to the weakly basic styrene anion exchange resin is 1: 1-1: 5, preferably 1: 1.5-1: 4; more preferably 1: 2-1: 3;

preferably, the basic resin catalyst is added in an amount of 0.2 to 20 wt%, preferably 0.3 to 18 wt%, more preferably 0.5 to 15 wt% based on the mass of 2, 2-iminodiethylsulfonic acid.

6. The method for producing a humectant according to any one of claims 2 to 5, characterized in that: the acetal comprises methylal, acetal, and propyl acetal, preferably methylal;

preferably, the acetal is added in an amount of 4 to 45 wt%, preferably 8 to 30 wt%, more preferably 10 to 20 wt% based on the mass of 2, 2-iminodiethylsulfonic acid.

7. The method for producing a humectant according to any one of claims 2 to 6, characterized in that: the reaction temperature is 100-150 ℃, preferably 110-140 ℃, and more preferably 120-135 ℃; the reaction pressure is 0.5 to 1MPa, preferably 0.7 to 0.9MPa, more preferably 0.8 to 0.85MPa in terms of gauge pressure; the reaction time is 20-50min, preferably 25-48min, more preferably 30-45 min.

8. The method for producing a humectant according to any one of claims 2 to 7, characterized in that: the reaction liquid obtained after the reaction can adopt two-stage reduced pressure flash evaporation, the first-stage reduced pressure flash evaporation realizes the recovery and reuse of acetal, the second-stage reduced pressure flash evaporation removes light component impurities generated by the reaction to obtain crude reaction liquid with lower purity, and then the crude reaction liquid is concentrated at high temperature to remove most of water, and the resin catalyst carried in the product is filtered to obtain mother liquid; cooling the mother liquor to obtain a crystalline product with higher purity; drying to obtain the N-fatty acid acyl disubstituted taurine.

9. The method for producing a humectant according to claim 8, characterized in that: the pressure of the first-stage reduced pressure flash evaporation is 0.2-0.7MPa, preferably 0.3-0.6MPa, and more preferably 0.4-0.5 MPa; the temperature of the first-stage reduced pressure flash evaporation is 80-100 ℃, preferably 83-98 ℃, and more preferably 85-90 ℃; the secondary flash pressure is 0.1-0.35MPa, preferably 0.1-0.3 MPa; more preferably 0.1-0.2 MPa; the secondary flash temperature is 50-100 ℃, preferably 55-80 ℃, and more preferably 65-75 ℃; the concentration of the reaction solution after removing light components is 20-50 wt%, preferably 30-48 wt%, and more preferably 35-45 wt%;

preferably, the crude reaction solution is concentrated at a temperature of 50 to 110 deg.C, preferably 80 to 100 deg.C, more preferably 85 to 95 deg.C; the concentration of the N-fatty acid acyl disubstituted taurine in the concentrated solution is 30 to 60 wt%, preferably 35 to 55 wt%, more preferably 45 to 50 wt%;

preferably, the mother liquor cooling crystallization temperature is 10-60 ℃, preferably 15-50 ℃, and more preferably 20-30 ℃;

preferably, the dry inlet air temperature is 185-240 ℃, preferably 190-235 ℃, and more preferably 200-230 ℃; the air outlet temperature is 80-125 ℃; operating pressure: 5-10 kPa;

preferably, the moisture content of the obtained solid N-fatty acid acyl disubstituted taurine is 0.2 wt% or less.

Technical Field

The invention relates to the field of cosmetic additives, in particular to a humectant and a preparation method thereof.

Background

Humectants (humectants) are a class of hygroscopic substances that absorb moisture from humid air. The pure humectant absorbs moisture from the environment, and the dilution remains constant after equilibrium moisture absorption is reached. The equilibrium moisture absorption depends on the nature of the humectant and the Relative Humidity (RH) of the environment. The humectant is moisturizing skin softening agent, and can be added into cosmetic to make into moisturizing cosmetic for delaying chapping caused by water evaporation. The humectant includes polyalcohol humectant, hyaluronic acid humectant, lactic acid and sodium lactate, sodium pyrrolidone glycolate, ceramide humectant, amide humectant, etc.

The humectant is an amide humectant, and most of the traditional amide bond synthesis utilizes the reaction of active carboxylic acid derivatives and amine, and a plurality of corrosive reagents and harmful substances are used in the process. The acid anhydride is used for preparing the amide, the reaction is generally catalyzed by alkali, the reaction can also be catalyzed by acid, common catalysts are sulfuric acid, peroxy acid and the like, and the material of related equipment is upgraded due to the corrosivity of materials, so that the project investment cost is increased. The most convenient method for synthesizing amides is to utilize the action of acyl halide and ammonia or amine. In general, the reaction of acid chlorides, acid bromides and amines is exothermic, and in some cases even very strong, so that the reaction is usually carried out under ice cooling, and a certain amount of solvent can also be used to slow down the reaction. Typical solvents are dichloroethane, diethyl ether, carbon tetrachloride, toluene, and the like. Since hydrogen halide is generated in the reaction, it is necessary to remove the hydrogen halide with a base to prevent it from forming a salt with the amine. As the organic base, triethylamine, pyridine and the like are usually used.

Because the related materials are of various types, the post-treatment difficulty of the product is increased, and the product refining steps are complicated.

Disclosure of Invention

The invention aims to provide a humectant and a preparation method thereof, the method adopts 2, 2-imino diethyl sulfonic acid (disubstituted taurine) and fatty acid chloride to react under the action of an alkaline resin catalyst and an acetal auxiliary agent to obtain N-fatty acid acyl disubstituted taurine, the reaction operation condition is mild, the sulfonic acid group in the taurine can be prevented from reacting to generate a byproduct, and the product purity is high; the prepared N-fatty acid acyl disubstituted taurine is used as a humectant, has stronger moisturizing effect than the traditional humectant, has low irritation to skin and is beneficial to skin absorption.

In order to solve the above problems, the present invention provides a novel humectant having the following structure:

where n is 3 to 13, preferably n is an odd number of 3 to 13, more preferably 5 to 11.

The invention also provides a preparation method of the humectant, which comprises the following steps: the humectant is prepared by reacting 2, 2-imino diethyl sulfonic acid and fatty acid chloride under alkaline conditions.

Preferably, the preparation method of the humectant is to react 2, 2-imino diethyl sulfonic acid and fatty acid chloride under the action of an alkaline resin catalyst and an acetal assistant to prepare the humectant.

Preferably, the structural formula of the 2, 2-imino-diethyl sulfonic acid is shown in the specification

Preferably, the preparation method comprises the following steps: adding fatty acid chloride and acetal into 2, 2-imino diethyl sulfonic acid aqueous solution, introducing into a reactor filled with an alkaline resin catalyst for reaction, and separating and purifying the reaction liquid to obtain the product.

Preferably, the concentration of the aqueous 2, 2-iminodiethylsulfonic acid solution is from 30 to 50 wt%, preferably from 35 to 48 wt%, more preferably from 40 to 45 wt%.

Preferably, the fatty acid chloride is a straight-chain saturated fatty acid chloride of C6-C16, preferably a straight-chain saturated fatty acid chloride of C8, C10, C12, C14, more preferably a straight-chain saturated fatty acid chloride of C10, C12.

Preferably, the molar ratio of 2, 2-iminodiethylsulfonic acid to fatty acid chloride is 1: 0.5-1: 1.5, preferably 1: 0.8-1: 1.2, more preferably 1: 0.9-1: 1.1.

preferably, the basic resin catalyst is one or a mixture of two or more of strongly basic styrene anion exchange resin and weakly basic styrene anion exchange resin, preferably, the basic resin catalyst is one or a mixture of two or more of 201X7 strongly basic styrene anion exchange resin and D301 macroporous weakly basic styrene anion exchange resin, preferably, the mass ratio of the D301 macroporous weakly basic styrene anion exchange resin or the mixed ion exchange resin of 201X7 strongly basic styrene anion exchange resin and D301 macroporous weakly basic styrene anion exchange resin is 1: 1-1: 5, preferably 1: 1.5-1: 4; more preferably 1: 2-1: 3.

preferably, the basic resin catalyst is added in an amount of 0.2 to 20 wt%, preferably 0.3 to 18 wt%, more preferably 0.5 to 15 wt% based on the mass of 2, 2-iminodiethylsulfonic acid.

Preferably, the acetal comprises methylal, acetal, propyl acetal and the like, preferably methylal, and the methylal with low boiling point can be removed by decompression and flash evaporation, so that the industrial production is easier to realize.

Preferably, the acetal is added in an amount of 4 to 45 wt%, preferably 8 to 30 wt%, more preferably 10 to 20 wt% based on the mass of 2, 2-iminodiethylsulfonic acid.

Preferably, the reaction temperature is 100-150 ℃, preferably 110-140 ℃, and more preferably 120-135 ℃; the reaction pressure is 0.5 to 1MPa, preferably 0.7 to 0.9MPa, more preferably 0.8 to 0.85MPa in terms of gauge pressure; the reaction time is 20-50min, preferably 25-48min, more preferably 30-45 min.

The reaction liquid obtained after the reaction can adopt two-stage reduced pressure flash evaporation, the first-stage reduced pressure flash evaporation realizes the recovery and reuse of acetal, the second-stage reduced pressure flash evaporation removes light component impurities generated by the reaction to obtain crude reaction liquid with lower purity, and then the crude reaction liquid is concentrated at high temperature to remove most of water, and the resin catalyst carried in the product is filtered to obtain mother liquid; and cooling the mother liquor to obtain a crystalline product with higher purity. And (3) spray drying the crystallized product with certain moisture content to obtain the final product N-fatty acid acyl disubstituted taurine.

Preferably, the pressure of the first-stage reduced pressure flash evaporation is 0.2-0.7MPa, preferably 0.3-0.6MPa, and more preferably 0.4-0.5 MPa; the temperature of the first-stage reduced pressure flash evaporation is 80-100 ℃, preferably 83-98 ℃, and more preferably 85-90 ℃; the secondary flash pressure is 0.1-0.35MPa, preferably 0.1-0.3 MPa; more preferably 0.1-0.2 MPa; the secondary flash temperature is 50-100 ℃, preferably 55-80 ℃, and more preferably 65-75 ℃; the concentration of the reaction solution after light components removal is 20 to 50 wt%, preferably 30 to 48 wt%, more preferably 35 to 45 wt%. And (3) concentrating the crude reaction liquid at high temperature to obtain mother liquid, cooling and crystallizing the mother liquid to separate out the N-fatty acid acyl disubstituted taurine, and drying to obtain the final product.

Preferably, the crude reaction solution is concentrated at a temperature of 50 to 110 ℃, preferably 80 to 100 ℃, more preferably 85 to 95 ℃; the concentration of the N-fatty acid acyl disubstituted taurine in the concentrate is 30 to 60% by weight, preferably 35 to 55% by weight, more preferably 45 to 50% by weight.

Preferably, the cooling crystallization temperature of the mother liquor is 10-60 ℃, preferably 15-50 ℃, and more preferably 20-30 ℃; the moisture content of the obtained solid matter is 2 wt% or less.

Preferably, the inlet air temperature of the spray drying is 185-240 ℃, preferably 190-235 ℃, and more preferably 200-230 ℃; the air outlet temperature is 80-125 ℃; operating pressure: 5-10 kPa; the moisture content of the obtained solid N-fatty acid acyl disubstituted taurine is 0.2 wt% or less.

The reaction principle of the invention is as follows: first is N (CH)₂CH₂SO₃H)₂Attack the C nucleus of the fatty acid chloride, with shifting of the electron pair of the C-Cl bond towards the Cl direction by electrostatic forces, with subsequent formation of one [ N … C … Cl ]]When the N-C bond is formed, the C-Cl bond is broken to generate the product.

The invention has the positive effects that:

(1) 2, 2-imino diethyl sulfonic acid prepared from food-grade taurine is used as a raw material for reaction, and the method is safe and reliable and has no toxic or side effect.

(2) The post-treatment process is simple, all by-products in the reaction solution are efficiently removed, the product with higher purity is obtained, the generated three wastes are less, and the three-waste treatment cost is effectively reduced.

(3) The reaction operation condition is mild, and the industrial production is easy to realize.

(4) If 2, 2-imino diethyl sulfonic acid is directly reacted with fatty acid chloride, the sulfonic acid group is easy to hydrolyze under alkaline conditions in the reaction process, acetal is used as a sulfonic acid group protecting reagent, and because the O atom orbit in the acetal has 2 unpaired electrons, two S atoms in the 2, 2-imino diethyl sulfonic acid and two O atoms in the acetal form a transition state substance, the sulfonic acid group is effectively protected. The transition state substance is unstable under the condition of first-stage flash evaporation, and the sulfonic group structure can be recovered.

(5) The prepared N-fatty acid acyl disubstituted taurine has excellent moisturizing effect as a novel moisturizing agent, and the addition amount of the N-fatty acid acyl disubstituted taurine in moisturizing cosmetics is reduced, so that the cost of the cosmetics is reduced. The main raw material for producing the N-fatty acid acyl disubstituted taurine is derived from food-grade taurine, is safe and healthy, has the lowest stimulation to skin, is more beneficial to the absorption of the skin, has poor skin feel and strong sticky feeling of the traditional glycerin, and the N-fatty acid acyl disubstituted taurine is more popular with consumers as a refreshing humectant with good skin quality.

Drawings

FIG. 1 is a comparison graph of the moisture retention performance of three kinds of moisture-retaining moisturizers in the application example under the conditions of the temperature of 28 ℃ and the relative humidity of RH 31%.

FIG. 2 is a comparison graph of the moisture retention performance of three kinds of moisture-retaining moisturizers in the application example under the conditions of the temperature of 30 ℃ and the relative humidity of RH 66%.

Detailed Description

The following examples are not intended to limit the scope of the present invention, and modifications and equivalents may be made thereto without departing from the spirit and scope of the present invention, which is defined in the appended claims.

201X7 strongly basic styrene anion exchange resin and D301 macroporous weakly basic styrene anion exchange resin were obtained from south Dacron resins, Inc., of Gallery; 2, 2-imino-diethyl-sulfonic acid and taurine are purchased from Yongan pharmaceutical industry of Zhanjiang; fatty acid chlorides were purchased from aladdin alastin.

The yield of the N-fatty acid acyl disubstituted taurine is obtained by analyzing and calculating liquid chromatogram provided with an ultraviolet detector, wherein the liquid chromatogram is an Agilent 1200 series liquid chromatogram provided with a C18 liquid chromatogram column with set column temperatureAt 40 ℃, acetonitrile and 0.05mol/L NaH₂PO₄The solution is a mobile phase, the flow rate is 1.0mL/min, the detection is carried out at the wavelength of 360nm by an ultraviolet detector, and the quantification is carried out by an external standard method. Before sample introduction, a sample is diluted properly by ultrapure water, added with excessive dinitrofluorobenzene solution for full derivatization, and then subjected to sample introduction analysis.

The N-fatty acid acyl disubstituted taurine is compounded into cosmetics, and the moisture retention of the cosmetics is characterized by measuring the moisture content in the horny layer by a SKICON200 type high-frequency conductivity tester.

Example 1

Putting 485g of 2, 2-imino-diethylsulfonic acid aqueous solution (40 wt%) into a 1L reactor filled with 2.3g of 201X7 strong-base styrene anion exchange resin and 4.6g of D301 macroporous weak-base styrene anion exchange resin, introducing 205g of lauric acid chloride (C12), adding 52.4g of auxiliary agent methylal, preheating the mixed material to the reaction temperature of 125 ℃, the pressure of the reactor being 0.8MPa, and the reaction time being 40 min; carrying out reduced pressure flash evaporation on the reaction liquid, wherein the pressure of primary flash evaporation is 0.4MPa, the temperature is 85 ℃, the pressure of secondary flash evaporation is 0.1MPa, the temperature is 65 ℃, and the concentration of the reaction liquid after removing light components and a small amount of resin is 35 wt%; and (3) further concentrating the reaction liquid after removing light components, wherein the concentration temperature is 90 ℃, and the concentration of the N-lauroyl disubstituted taurine in the concentrated liquid is 45 wt%. And then cooling to 25 ℃ for crystallization, wherein the yield per pass of the crystallized N-lauroyl disubstituted taurine is 80%, and the obtained N-lauroyl disubstituted taurine with the moisture content of less than 2 wt% is subjected to spray drying to remove most of water instantly, so that solid substances in the material are dried into powder. Wherein the air inlet temperature is 210 ℃; the air outlet temperature is 110 ℃, and the operating pressure is 6 kPa; the moisture content of the solid matter was 0.2 wt%. Data obtained from N-lauroyl disubstituted taurine nuclear magnetic chromatogram: chemical shift 0.7-1 multiplet 3H; chemical shift 1.2-1.6 multiple peak 18H; chemical shift 2 singlet 2H; chemical shift 2.3-2.5 multiple peak 2H; chemical shifts 3.6-3.8 multiple peak 8H.

Example 2

Putting 455g of 2, 2-imino diethyl sulfonic acid aqueous solution (42 wt%) into a 1L reactor filled with 5.3g of 201X7 strong-base styrene anion exchange resin and 26.3g of D301 macroporous weak-base styrene anion exchange resin, introducing 170g of hexanoic acid chloride (C6), adding 23.4g of auxiliary agent acetal, preheating the mixed material to the reaction temperature of 135 ℃, the pressure of the reactor being 0.85MPa, and the reaction time being 45 min; carrying out reduced pressure flash evaporation on the reaction liquid, wherein the pressure of primary flash evaporation is 0.7MPa, the temperature is 100 ℃, the pressure of secondary flash evaporation is 0.2MPa, the temperature is 80 ℃, and the concentration of the reaction liquid after removing light components and a small amount of resin is 35 wt%; and (3) further concentrating the reaction liquid after removing the light components, wherein the concentration temperature is 100 ℃, and the concentration of the N-caproic acid acyl disubstituted taurine in the concentrated liquid is 48 wt%. And then cooling to 28 ℃ for crystallization, wherein the once-through yield of the N-acyl-caproate disubstituted taurine after crystallization is 71 percent, and the obtained N-acyl-caproate disubstituted taurine with the moisture content of less than 2 weight percent is subjected to spray drying to remove most of water instantly, so that solid substances in the material are dried into powder. Wherein the inlet air temperature is 205 ℃; the air outlet temperature is 115 ℃, and the operating pressure is 7 kPa; the moisture content of the solid matter was 0.2 wt%.

Example 3

Placing 608g of 2, 2-imino diethyl sulfonic acid aqueous solution (40 wt%) in a 1L reactor filled with 43g of D301 macroporous weak base styrene anion exchange resin, introducing 310g of myristoyl chloride (C14), adding 35g of auxiliary agent of propyl acetal, preheating the mixed material to the reaction temperature of 140 ℃, the pressure of the reactor is 0.9MPa, and the reaction time is 48 min; carrying out reduced pressure flash evaporation on the reaction liquid, wherein the pressure of primary flash evaporation is 0.6MPa, the temperature is 100 ℃, the pressure of secondary flash evaporation is 0.3MPa, the temperature is 98 ℃, and the concentration of the reaction liquid after removing light components and a small amount of resin is 20 wt%; and (3) further concentrating the reaction liquid after removing light components, wherein the concentration temperature is 110 ℃, and the concentration of the N-myristoyl disubstituted taurine in the concentrated liquid is 48 wt%. And then cooling to 15 ℃ for crystallization, wherein the once-through yield of the crystallized N-myristoyl disubstituted taurine is 65%, and the obtained N-myristoyl disubstituted taurine with the moisture content of less than 2 wt% is subjected to spray drying to remove most of water instantly, so that solid substances in the materials are dried into powder. Wherein the inlet air temperature is 235 ℃; the air outlet temperature is 125 ℃, and the operating pressure is 10 kPa; the moisture content of the solid matter was 0.2 wt%.

Example 4

Placing 506g of 2, 2-imino diethyl sulfonic acid aqueous solution (35 wt%) in a 1L reactor filled with 4.3g of 201X7 strong-base styrene anion exchange resin and 17.3g of D301 macroporous weak-base styrene anion exchange resin, introducing 192g of palmitoyl chloride (C16), adding 75g of auxiliary agent methylal, preheating the mixed material to the reaction temperature of 150 ℃, the pressure of the reactor being 1MPa, and the reaction time being 50 min; carrying out reduced pressure flash evaporation on the reaction liquid, wherein the pressure of primary flash evaporation is 0.2MPa, the temperature is 80 ℃, the pressure of secondary flash evaporation is 0.1MPa, the temperature is 50 ℃, and the concentration of the reaction liquid after removing light components and a small amount of resin is 30 wt%; and (3) further concentrating the reaction liquid after removing the light components, wherein the concentration temperature is 110 ℃, and the concentration of the N-palmitoyl disubstituted taurine in the concentrated liquid is 55 wt%. And then cooling to 20 ℃ for crystallization, wherein the once-through yield of the N-palmitoyl disubstituted taurine after crystallization is 63 percent, and the obtained N-palmitoyl disubstituted taurine with the moisture content of less than 2 weight percent is subjected to spray drying to remove most of water instantly, so that solid substances in the material are dried into powder. Wherein the air inlet temperature is 190 ℃; the air outlet temperature is 100 ℃, and the operating pressure is 8 kPa; the moisture content of the solid matter was 0.2 wt%.

Example 5

Putting 355g2, 2-imino diethyl sulfonic acid aqueous solution (48 wt%) in a 1L reactor filled with 5g201X7 strong-base styrene anion exchange resin and 5g D301 macroporous weak-base styrene anion exchange resin, introducing 131g lauric acid acyl chloride, adding 8g auxiliary agent methylal, preheating the mixed material to the reaction temperature of 100 ℃, the pressure of the reactor being 0.5MPa, and reacting for 30 min; carrying out reduced pressure flash evaporation on the reaction liquid, wherein the pressure of primary flash evaporation is 0.5MPa, the temperature is 95 ℃, the pressure of secondary flash evaporation is 0.25MPa, the temperature is 90 ℃, and the concentration of the reaction liquid after removing light components and a small amount of resin is 25 wt%; and (3) further concentrating the reaction liquid after removing the light components, wherein the concentration temperature is 80 ℃, and the concentration of the N-lauroyl disubstituted taurine in the concentrated liquid is 30 wt%. And then cooling to 30 ℃ for crystallization, wherein the once-through yield of the crystallized N-lauroyl disubstituted taurine is 75 percent, and the obtained N-lauroyl disubstituted taurine with the moisture content of less than 2 weight percent is subjected to spray drying to remove most of water instantly, so that solid substances in the material are dried into powder. Wherein the inlet air temperature is 200 ℃; the air outlet temperature is 105 ℃, and the operation pressure is 5 kPa; the moisture content of the solid matter was 0.2 wt%.

Comparative example 1

Putting 485g of 2, 2-imino diethyl sulfonic acid aqueous solution (40 wt%) into a 1L reactor filled with 2.3g of 201X7 strong-base styrene anion exchange resin and 4.6g of D301 macroporous weak-base styrene anion exchange resin, introducing 205g of lauric acid chloride (C12) without adding auxiliary agent methylal, preheating the mixed material to the reaction temperature of 125 ℃, the pressure of the reactor being 0.8MPa, and the reaction time being 40 min; carrying out reduced pressure flash evaporation on the reaction liquid, wherein the pressure of primary flash evaporation is 0.4MPa, the temperature is 85 ℃, the pressure of secondary flash evaporation is 0.1MPa, the temperature is 65 ℃, and the concentration of the reaction liquid after removing light components and a small amount of resin is 35 wt%; and (3) further concentrating the reaction liquid after removing light components, wherein the concentration temperature is 90 ℃, and the concentration of the N-lauroyl disubstituted taurine in the concentrated liquid is 45 wt%. Then cooling to 25 ℃ for crystallization, and obtaining the yield of the N-lauric acyl disubstituted taurine after crystallization by one-way process of 49 percent.

Comparative example 2

Placing 405g of taurine aqueous solution (40 wt%) in a 1L reactor filled with 2.7g of 201X7 strongly basic styrene anion exchange resin and 5.4g of D301 macroporous weakly basic styrene anion exchange resin, introducing 290g of lauric acid acyl chloride (C12), adding 24.3g of auxiliary agent methylal, preheating the mixed material to the reaction temperature of 130 ℃, the pressure of the reactor being 0.83MPa, and the reaction time being 42 min; carrying out reduced pressure flash evaporation on the reaction liquid, wherein the pressure of the primary flash evaporation is 0.45MPa, the temperature is 87 ℃, the pressure of the secondary flash evaporation is 0.15MPa, the temperature is 70 ℃, and the concentration of the reaction liquid after removing light components and a small amount of resin is 38 wt%; and (3) further concentrating the reaction liquid after removing light components, wherein the concentration temperature is 90 ℃, and the concentration of the N-lauroyl-substituted taurine in the concentrated liquid is 45 wt%. And then cooling to 25 ℃ for crystallization, wherein the yield of the crystallized N-lauroyl-substituted taurine is 78% per pass, and the obtained N-lauroyl-substituted taurine with the moisture content of less than 2 wt% is subjected to spray drying to remove most of water instantly, so that solid substances in the material are dried into powder. Wherein the inlet air temperature is 215 ℃; the air outlet temperature is 115 ℃, and the operating pressure is 6 kPa; the moisture content of the solid matter was 0.2 wt%.

Wherein the structural formula of the N-lauric acyl-substituted taurine is as follows:

application example:

the fatty acid acyl disubstituted taurine prepared by the embodiment of the invention is used as a humectant to prepare the moisturizing moisturizer according to the following formula.

TABLE 1 formulation of moisturizing lotion (the amount of each component added is its mass)

Table 2: comparison of moisturizing Properties of different fatty acid acyl disubstituted taurine

Note: 24h moisture loss rate test conditions: the temperature is 28 ℃ and the relative humidity is RH 31%.

The smaller the water loss rate, the better the moisturizing effect. The experimental results in the table and fig. 1 and 2 show that the N-lauroyl-disubstituted taurine has very poor moisturizing effect and basically no moisturizing effect, and the N-lauroyl-disubstituted taurine of the invention has obvious moisturizing effect, and the moisturizing effect of the moisturizing moisturizer is obviously better than that of the control sample (glycerin) under two different conditions.