阅读说明：本技术 1,2-己二醇及其纯化方法和用途 (1, 2-hexanediol and purification method and application thereof ) 是由 何成涛 郭朋 朱文峰 于 2021-01-20 设计创作，主要内容包括：本申请公开了一种1,2-己二醇及其纯化方法和用途。本申请中,提供了一种1,2-己二醇的纯化方法,所述纯化方法包括以下步骤：(1)用金属硼氢化物处理1,2-己二醇粗产品。本申请提供的纯化1,2-己二醇的方法可去除1,2-己二醇产品中的气味杂质,使1,2-己二醇产品极低或无中药气味,更适宜在高级化妆品中使用。本申请提供的纯化1,2-己二醇的方法,工艺简单、成本低廉,易于工业化。(The application discloses 1, 2-hexanediol and a purification method and application thereof. In the present application, there is provided a process for the purification of 1, 2-hexanediol, the process comprising the steps of: (1) the crude 1, 2-hexanediol is treated with a metal borohydride. The method for purifying the 1, 2-hexanediol can remove odor impurities in the 1, 2-hexanediol product, so that the 1, 2-hexanediol product has extremely low or no traditional Chinese medicine odor, and is more suitable for being used in high-grade cosmetics. The method for purifying the 1, 2-hexanediol has the advantages of simple process, low cost and easiness in industrialization.)

1. A method for purifying 1, 2-hexanediol, comprising the steps of: (1) the crude 1, 2-hexanediol is treated with a metal borohydride.

2. The purification method according to claim 1, wherein the metal borohydride is an alkali metal borohydride.

3. The purification method according to claim 1, wherein the metal borohydride is sodium borohydride or potassium borohydride.

4. The purification method according to claim 1, wherein the metal borohydride accounts for 0.05-0.3% of the total mass of the reaction system.

5. The purification method according to any one of claims 1 to 4, wherein in step (1), the treatment comprises step (A) of low-temperature stirring and (B) of distillation under reduced pressure.

6. The purification method according to claim 5, wherein in the step (A), the low-temperature stirring temperature is 10-20 ℃;

and/or in the step (A), the low-temperature stirring time is 5-14 hours.

7. The purification method according to claim 5, wherein in the step (A), purified water is added dropwise during at least part of the stirring operation in the low-temperature stirring, and the total amount of the added purified water is 12-18% of the total weight of the reaction system.

8. The purification process according to claim 5, wherein in step (B), the distillation under reduced pressure is carried out in the presence of an oil pump;

and/or in the step (B), the vacuum degree of the reduced pressure distillation is 30-50 pa;

and/or in the step (B), the fraction collected during the reduced pressure distillation is a fraction at the temperature of 60-65 ℃.

9. 1, 2-hexanediol produced by the purification method of any one of claims 1 to 8.

10. Use of the 1, 2-hexanediol of claim 9 as a cosmetic additive.

Technical Field

The embodiment of the invention relates to the field of cosmetic manufacturing, in particular to 1, 2-hexanediol and a purification method and application thereof.

Background

1, 2-hexanediol is an important chemical raw material, and is widely applied to inks of color ink-jet printers, high-grade cosmetics and synthetic raw materials in the pharmaceutical industry. 1, 2-hexanediol is a colorless, transparent, viscous liquid that can be mixed with a variety of organic compounds in any proportion and is readily soluble in water. Wherein in the field of cosmetics, 1, 2-hexanediol is a good additive because it has no irritation to the human body and has good moisture retention and antibacterial effects. The traditional method for synthesizing 1, 2-hexanediol generally takes 1-hexene as a starting material, and generates the 1, 2-hexanediol through two processes of oxidizing agent epoxidation and hydrolysis, and the market feeds back that the product obtained by the method contains unpleasant smell similar to that of traditional Chinese medicines, and cannot be directly used in the cosmetic market. If odorless 1, 2-hexanediol is to be obtained, the current method used in the industry is repeated rectification to obtain a product of very high purity, typically up to 99.99%. The production method has large loss and low yield, and leads the selling price of the 1, 2-hexanediol which is directly used in the cosmetic industry to be more than 3 times higher than that of the 1, 2-hexanediol with odor.

Therefore, there is still a need to develop a method for purifying 1, 2-hexanediol, which has simple process, low cost and easy industrialization.

Disclosure of Invention

The invention aims to provide a method for purifying 1, 2-hexanediol, which has simple process and low cost and is easy to industrialize, so that odor impurities in a 1, 2-hexanediol crude product can be removed at low cost, and the method is suitable for being used in high-grade cosmetics.

In order to solve the above technical problems, a first aspect of the present invention provides a method for purifying 1, 2-hexanediol, comprising the steps of: (1) the crude 1, 2-hexanediol is treated with a metal borohydride.

The 1, 2-hexanediol crude product can be 1, 2-hexanediol which is prepared by a conventional method and is not purified, and specifically, the 1, 2-hexanediol crude product can be 1, 2-hexanediol which is obtained by using 1-hexene as a starting material, firstly carrying out epoxidation by using an oxidant and then carrying out hydrolysis.

In the step (1), the metal borohydride is preferably an alkali metal borohydride, and more preferably sodium borohydride or potassium borohydride.

In the step (1), the metal borohydride preferably accounts for 0.05-0.3% of the total mass of the reaction system, and more preferably accounts for 0.1-0.2% of the total mass of the reaction system.

In the step (1), the treatment comprises the steps of (A) low-temperature stirring and (B) reduced pressure distillation.

In the step (A), the low-temperature stirring temperature is preferably 10-20 ℃, and more preferably 15-20 ℃.

In the step (A), the time of low-temperature stirring is preferably 5 to 14 hours, and more preferably 10 to 12 hours.

In the step (A), during the low-temperature stirring, purified water is dripped while at least part of stirring operation is carried out, and the total dripping amount of the purified water is preferably 12-18% of the total weight of the reaction system, and more preferably 12-16%.

In step (B), the distillation under reduced pressure is preferably carried out in the presence of an oil pump.

In the step (B), the vacuum degree of the reduced pressure distillation is preferably 30-50 pa.

In the step (B), the fraction collected during the reduced pressure distillation is a fraction at the temperature of 60-65 ℃.

The second aspect of the present invention also provides 1, 2-hexanediol prepared by the above method for purifying 1, 2-hexanediol, wherein the GC purity of the 1, 2-hexanediol is preferably 98.0% or more, more preferably 99.0% or more.

The third aspect of the present invention also provides the use of the above-mentioned 1, 2-hexanediol as a cosmetic additive.

The above preferred conditions can be arbitrarily combined to obtain preferred embodiments of the present invention without departing from the common general knowledge in the art.

The reagents and starting materials used in the present invention are commercially available.

Compared with the prior art, the invention has at least the following advantages:

(1) the method for purifying the 1, 2-hexanediol provided by the first aspect of the invention can remove odor impurities in the 1, 2-hexanediol crude product, so that the 1, 2-hexanediol product has extremely low or no traditional Chinese medicine odor, and is more suitable for being used in high-grade cosmetics.

(2) The method for purifying the 1, 2-hexanediol provided by the first aspect of the invention has the advantages of simple process, low cost and easy industrialization.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the following describes each embodiment of the present invention in detail with reference to the embodiments. However, it will be appreciated by those of ordinary skill in the art that numerous technical details are set forth in order to provide a better understanding of the present application in various embodiments of the present invention. However, the technical solution claimed in the present application can be implemented without these technical details and various changes and modifications based on the following embodiments.

The invention aims at the problems of complex production process, high cost and difficult industrialization of odorless 1, 2-hexanediol for cosmetics, and the inventor conducts detailed research and speculates that byproducts such as incomplete oxidation, excessive oxidation or incomplete hydrolysis and the like exist in the process of synthesizing the 1, 2-hexanediol, the content of the byproducts is extremely low, the structure is uncertain, the detection of a general detection method is difficult, the attention of manufacturers is not attracted, and the finished product 1, 2-hexanediol contains the odor similar to that of a traditional Chinese medicine, so that the inventor provides a method for purifying the 1, 2-hexanediol with low cost, and the odor of the product is obviously removed by converting the trace odorous byproducts into odorless substances.

Example 1

The method comprises the following steps: preparation of 1, 2-hexanediol as crude product

In a 500mL three-necked flask, a thermometer, a dropping funnel and a low-temperature reflux condenser were provided. 140.0g of 88% formic acid, 75.0g of 1-hexene were added in succession at room temperature. The temperature is raised to 50 ℃ while stirring, and 110.0g of 30% hydrogen peroxide is slowly dropped. Stirring at 55 deg.C until the reaction is complete. 275.0g of 40% NaOH aqueous solution is dripped, and the mixture is stirred for 1 hour at 20-25 ℃ after dripping. The reaction system is kept stand for layering, and the upper layer is taken to be rectified under vacuum to obtain 47.6g of main fraction of the product, the GC purity is 99.56%, the moisture content is 0.23%, and the yield of the main fraction is 45.33%.

Step two: purification of 1, 2-hexanediol crude product by addition of sodium borohydride

And (2) adding 320g of the product prepared in the step (1) into a 500mL three-neck flask, slowly adding 0.64g of sodium borohydride solid powder at room temperature, cooling to 5-10 ℃, and stirring for 15 minutes. Dropping 54.0g of purified water at 5-10 ℃, stirring for 30 minutes at 5-10 ℃ after dropping, and then stirring for 10 hours at 15-20 ℃. Quickly distilling under reduced pressure by using an oil pump under vacuum of 30-50 pa, and collecting 287g of main fraction at the temperature of 60-65 ℃, wherein the yield is 89.7%; the GC purity was 99.50%.

EXAMPLE 2 crude purification of 1, 2-hexanediol by addition of potassium borohydride

The method comprises the following steps: preparation of 1, 2-hexanediol as crude product

In a 500mL three-necked flask, a thermometer, a dropping funnel and a low-temperature reflux condenser were provided. 140.0g of 88% formic acid, 75.0g of 1-hexene were added in succession at room temperature. The temperature is raised to 50 ℃ while stirring, and 110.0g of 30% hydrogen peroxide is slowly dropped. Stirring at 55 deg.C until the reaction is complete. 275.0g of 40% NaOH aqueous solution is dripped, and the mixture is stirred for 1 hour at 20-25 ℃ after dripping. The reaction system is kept stand for layering, and the upper layer is taken to be rectified under vacuum to obtain 47.6g of main fraction of the product, the GC purity is 99.56%, the moisture content is 0.23%, and the yield of the main fraction is 45.33%.

Step two: adding potassium borohydride to purify 1, 2-hexanediol crude product

200g of 99.5% pure product prepared in example 1 is added into a 500mL three-neck flask, 1g of potassium borohydride solid powder is slowly added at room temperature, and the mixture is cooled to 5-10 ℃ and stirred for 15 minutes. Dropping 40.0g of purified water at 5-10 ℃, stirring for 30 minutes at 5-10 ℃ after dropping, and then stirring for 10 hours at 15-20 ℃. Quickly distilling under reduced pressure by an oil pump under vacuum of 30-50 Pa, and collecting 170g of main fraction at the temperature of 60-65 ℃, wherein the yield is 85.0%; the GC purity was 99.50%.

Comparative example 1

In a 500mL three-necked flask, a thermometer, a dropping funnel and a low-temperature reflux condenser were provided. 140.0g of 88% formic acid, 75.0g of 1-hexene were added in succession at room temperature. The temperature is raised to 50 ℃ while stirring, and 110.0g of 30% hydrogen peroxide is slowly dropped. Stirring at 55 deg.C until the reaction is complete. 275.0g of 40% NaOH aqueous solution is dripped, and the mixture is stirred for 1 hour at 20-25 ℃ after dripping. The reaction system is kept stand for layering, and the upper layer is taken to be rectified under vacuum to obtain 47.6g of main fraction of the product, the GC purity is 99.56%, the moisture content is 0.23%, and the yield of the main fraction is 45.33%.

Comparative example 2

The 1, 2-hexanediol product from a manufacturer in a certain country was used as comparative example 2.

Comparative example 3

Cosmetic grade 1, 2-hexanediol product manufactured from KOWA imported 1, 2-hexanediol product was taken as comparative example 3.

Test example 1 smell determination

One drop of the product of example 1 was taken with a 3mL plastic dropper and dropped into 20mL of open-mouthed clear water at a temperature of 50 ℃ or higher. After dripping, the liquid quickly approaches the nose and the smell is distinguished.

In other examples and comparative examples, the odor was identified in the same manner as in example 1, and the results of the comparison were identified in Table 1.

TABLE 1

It will be understood by those of ordinary skill in the art that the foregoing embodiments are specific examples for carrying out the invention, and that various changes in form and details may be made therein without departing from the spirit and scope of the invention in practice.