A method for the preparation of cosmetic grade 1,3-butanediol

Abstract

The application provides a preparation method of cosmetic-grade 1,3-butanediol. After industrial-grade 1,3-butanediol is washed and extracted by a buffer solution and subjected to rectification treatment, odorless 1,3-butanediol is prepared, the content of the 1,3-butanediol is greater than 99.8%, key impurities are not detected, the product is odorless, and the product can be applied to the field of cosmetics.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of chemical industry, and relates to a preparation method of cosmetic-grade 1,3-butanediol. BACKGROUND

[0002] 1,3-butanediol is a viscous, colorless, transparent and odorless water-soluble liquid. Due to low biological toxicity and good stability, 1,3-butanediol is used as a cosmetic raw material. As a cosmetic raw material, 1,3-butanediol has characteristics such as moisturizing effect and antibacterial property, and therefore is used in products such as shampoo, emulsion and moisturizer. When used in cosmetics, 1,3-butanediol with little odor is required. 1,3-butanediol itself has little odor, but odor can be generated due to by-products or impurities generated during the manufacturing process.

[0003] The main manufacturing method of 1,3-butanediol is to condense acetaldehyde to obtain butanol aldehyde (3-hydroxybutanal), and then to hydrogenate it. However, during the reaction, substances such as acetal and aldehyde are generated, which cause the product 1,3-butanediol to have an odor:

[0004]

[0005] CN 113557221 reports that the product odor is controlled by distillation, but the odor impurities are not completely removed, and the product has an odor when configured as an aqueous solution. CN115400706 reports that the odor is removed by using water vapor distillation, but this step is complicated and has high energy consumption, which is not conducive to large-scale industrial production. CN114890869 reports that the odor is removed by using esterification and extraction, but the reaction steps are complicated, new impurities are introduced, and the product is difficult to meet the requirements.

[0006] In summary, it is urgent to develop a process for removing odor from 1,3-butanediol to solve the problems existing in the prior art and process, and to facilitate industrial production. SUMMARY

[0007] In view of the above problems existing in the prior art, the present application provides a method for preparing 1,3-butanediol, which obtains cosmetic-grade 1,3-butanediol by extraction and distillation. The method has the advantages of simple process, high product quality and easy industrial production.

[0008] To achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows:

[0009] A method for preparing cosmetic-grade 1,3-butanediol, comprising: obtaining cosmetic-grade 1,3-butanediol by extracting and distilling industrial-grade 1,3-butanediol.

[0010] In the method of the present application, the purity of the industrial-grade 1,3-butanediol is preferably above 99%.

[0011] In the method of the present application, further, the industrial-grade 1,3-butanediol is first prepared into a mixed solution with a buffer solution before extraction, and the concentration of 1,3-butanediol in the mixed solution is 10-90%, preferably 30-70%;

[0012] Further, the pH value of the buffer solution is controlled at 3-7, and the buffer system is preferably an acetic acid / sodium acetate system, a sodium dihydrogen phosphate / disodium hydrogen phosphate system, a citric acid / sodium citrate system, a potassium hydrogen phosphate / potassium dihydrogen phosphate system, and further preferably the citric acid / sodium citrate system.

[0013] In the method of the present application, further, the organic solvent used for extraction is a water-immiscible solvent, and preferably toluene, cyclohexane, n-hexane, butyl acetate, ethyl acetate, n-hexane, methyl tetrahydrofuran, methyl isobutyl ketone, and further preferably cyclohexane, methyl tetrahydrofuran, and methyl isobutyl ketone; and the mass ratio of the amount of the organic solvent to the amount of water is preferably 0.5-1.

[0014] Further, in the extraction, the mixing of the mixed solution and the organic solvent can use a reaction kettle, a static mixer+phase separation kettle, a rotating disc extraction tower, a packed tower, etc., and preferably the rotating disc extraction tower and the packed tower.

[0015] In the method of the present application, the aqueous phase after extraction is a 1,3-butanediol aqueous solution, which is subjected to rectification to obtain cosmetic-grade 1,3-butanediol.

[0016] Further, in the rectification process, the oxygen content in the control system is controlled to be less than 10 ppm.

[0017] In the method of the present application, the prepared 1,3-butanediol has a colority of <10 and a content of >99.8%, and no odor impurities are detected.

[0018] Compared with the prior art, the technical scheme of the present application has the following advantages:

[0019] 1) The use of an acidic buffer solution for extraction improves the removal effect of acetal impurities, and at the same time avoids the deterioration of the product under acidic conditions;

[0020] 2) By controlling the oxidation amount of the rectification system, the generation of aldehyde impurities is avoided, and the product has low colority and no odor. DETAILED DESCRIPTION

[0021] The present application will be further described below through specific examples, and the examples described in the present application are only used to illustrate the present application and do not limit the scope of the present application.

[0022] The reagents and solvents used in the present application can be purchased from Aladdin Reagent Company.

[0023] Industrial-grade 1,3-butanediol: Wanhua Chemical, 99.5%.

[0024] Example 1

[0025] 500g of industrial grade 1,3-butanediol was mixed with 500g of aqueous solution (acetic acid / sodium acetate system, pH = 6), and then the mixed aqueous solution was stirred with 300g of cyclohexane in a reaction kettle for 20 min, and then the water phase was separated and refined in a rectifying column, the pressure was 10 kPa, the number of plates was 30, the light components were taken out from the top of the column, and the product was taken out from the bottom of the column, and the oxygen content of the system was controlled to be less than 10 ppm during the process. 480g of 1,3-butanediol was obtained by rectification, the purity of the product was 99.92%, and impurities A, impurities B and butyraldehyde were not detected, and the color of the product was 6 Hazen, which was recorded as sample 1.

[0026] Example 2

[0027] 5000g of industrial grade 1,3-butanediol was mixed with 2000g of aqueous solution (sodium dihydrogen phosphate / sodium hydrogen phosphate system, pH = 7), and then the aqueous solution was extracted and separated in a rotating disc extraction column with 1000g of methyl isobutyl ketone, and then the water phase was refined in a rectifying column, the pressure was 5 kPa, the number of plates was 30, the light components were taken out from the top of the column, and the product was taken out from the bottom of the column, and the oxygen content of the system was controlled to be less than 10 ppm during the process. 4936g of 1,3-butanediol was obtained by rectification, the purity of the product was 99.87%, and impurities A, impurities B and butyraldehyde were not detected, and the color of the product was 2 Hazen, which was recorded as sample 2.

[0028] Example 3

[0029] 5000g of industrial grade 1,3-butanediol was mixed with 1000g of aqueous solution (citric acid / sodium citrate system, pH = 4), and then the aqueous solution was extracted and separated in a rotating disc extraction column with 500g of methyltetrahydrofuran, and then the water phase was refined in a rectifying column, the pressure was 8 kPa, the number of plates was 30, the light components were taken out from the top of the column, and the product was taken out from the bottom of the column, and the oxygen content of the system was controlled to be less than 10 ppm during the process. 4918g of 1,3-butanediol was obtained by rectification, the purity of the product was 99.89%, and impurities A, impurities B and butyraldehyde were not detected, and the color of the product was 2 Hazen, which was recorded as sample 3.

[0030] Comparative Example 1

[0031] 500g of industrial grade 1,3-butanediol was mixed with 500g of aqueous solution (sodium dihydrogen phosphate / sodium hydrogen phosphate system, pH = 8), and then the aqueous solution was stirred with 300g of cyclohexane in a reaction kettle for 20min, and then the water phase was separated and refined in a rectifying column, the pressure was 10kPa, the number of plates was 30, the light components were taken out from the top of the column, and the product was taken out from the bottom of the column, and the oxygen content of the system was controlled to be less than 10ppm during the process, and 490g of 1,3-butanediol was obtained by rectification, the purity of the product was 99.85%, the impurity A was 2ppm, the impurity B was 3ppm, and the butyl aldehyde was not detected, and the colority of the product was 6Hazen, which was recorded as sample 4.

[0032]

Comparative Example 2

[0033] 500g of industrial grade 1,3-butanediol was mixed with 500g of aqueous solution (acetic acid / sodium acetate system, pH = 6), and then the aqueous solution was stirred with 300g of cyclohexane in a reaction kettle for 20min, and then the water phase was separated and refined in a rectifying column, the pressure was 10kPa, the number of plates was 30, the light components were taken out from the top of the column, and the product was taken out from the bottom of the column, and the oxygen content of the system was controlled to be less than 10ppm during the process, and 490g of 1,3-butanediol was obtained by rectification, the purity of the product was 99.85%, the impurity A was 2ppm, the impurity B was 3ppm, and the butyl aldehyde was not detected, and the colority of the product was 6Hazen, which was recorded as sample 4.

[0034] The prepared sample was prepared into an aqueous solution of different concentrations for odor test, and each sample was identified by 10 people, and the results were as follows.

[0035]

[0036]

[0037] According to the test results of the above examples and comparative examples, the cosmetic 1,3-butanediol obtained by the acid buffer solution washing and extraction rectification method has the advantages of simple operation and industrialization compared with the prior art in the comparative examples.

[0038] The above is only an example of the embodiment of the present application, and it should be pointed out that for ordinary skilled in the art, without departing from the method of the present application, a number of improvements and supplements can also be made, which should be considered as the protection scope of the present application.

Claims

1. A process for the preparation of cosmetic grade 1,3-butanediol, characterized in that, The industrial grade 1,3-butanediol is extracted and rectified to obtain the cosmetic grade 1,3-butanediol; The industrial grade 1,3-butanediol is first mixed with a buffer solution to form a mixed solution before extraction, and the pH value of the buffer solution is 3-7; and the oxygen content in the control system is less than 10 ppm during rectification.

2. The production method according to claim 1, characterized by, The buffer solution is at least one of acetic acid / sodium acetate system, sodium dihydrogen phosphate / disodium hydrogen phosphate system, citric acid / sodium citrate system, and potassium hydrogen phosphate / potassium dihydrogen phosphate system.

3. The production method according to claim 1 or 2, characterized by, The concentration of 1,3-butanediol in the mixed solution is 10-90 wt%.

4. The production method according to claim 3, characterized by, The concentration of 1,3-butanediol in the mixed solution is 30-70 wt%.

5. The method of any one of claims 1-2, wherein, The organic solvent used for extraction is a water-immiscible solvent.

6. The method of any one of claims 1-2, wherein, The organic solvent used for extraction is at least one of toluene, cyclohexane, n-hexane, butyl acetate, ethyl acetate, methyl tetrahydrofuran, and methyl isobutyl ketone.

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