KR20190030058A - Purifying method of alkanediol - Google Patents

Abstract

A method for purifying alkanediols according to the present invention comprises: a buffer solution processing step of mixing crude alkanediols with a borate buffer solution; a deodorization step of deodorizing the same by adding activated carbon after the buffer solution processing step; and a purified water processing step of mixing the crude alkanediols having passed through the deodorization step with purified water. When alkanediols are purified by the method according to the present invention, it is possible to manufacture purified alkanediols in which no unpleasant odor or bad odor is exhibited.

Description

Purifying method of alkanediol < RTI ID = 0.0 >

The present invention relates to a purification method for purifying an alkane diol using a borate buffer solution, activated carbon and purified water.

The alkanediol is a kind of polyhydric alcohol. In particular, the 1,2-alkanediol has a moisture resistance similar to propylene glycol and the like in the range of not more than 8 carbon atoms. Furthermore, it has excellent repellency as well as excellent moisture retention and is relatively low in toxicity and is widely used for moisturizing cosmetics, hygiene products or disinfectants.

These alkanediols are typically prepared by reacting alkenes with hydrogen peroxide under a metal catalyst. However, the method of producing such an alkane diol has a problem in that a large amount of the side reaction product is present together with the desired alkane diol, and unreacted alkene remains. As a result, the final product, alkanediol, has a problem of containing various impurities such as ketones, carboxylic acids, aldehydes, alkenes and derivatives thereof. Furthermore, in the case of solvents used for refining the alkane diol, there is a problem that the alkane diol is slightly mixed with the finally produced alkane diol to give an unpleasant smell to the alkane diol.

As a result of such a problem, it has been difficult to use it in cosmetics even though it has excellent moisture and antibacterial power as described above. In order to overcome such a problem, Korean Patent Publication No. 10-1584727 discloses a method of separating a mixture containing an alkane diol and a carbonate compound and then producing a purified alkane diol through a treatment such as distillation. However, even in such a case, there is a problem that odor remains due to some mixed carbonate compounds.

Korean Patent Publication No. 10-1584727

It is an object of the present invention to provide an alkane diol purification method which removes impurities and hardly generates unpleasant odors.

Another object of the present invention is to provide an alkane diol purification method capable of removing the odor of an alkane diol in a relatively simple manner.

The method for purifying alkane diol according to the present invention comprises

A buffer solution processing step of mixing the crude alkane diol and the borate buffer solution;

A deodorization step of deodorizing by adding activated carbon after the buffer solution treatment step; And

And a purified water treatment step of mixing the crude alkanediol passed through the deodorization step with purified water.

In the alkane diol purification method according to an embodiment of the present invention, the pH of the borate buffer solution may be 9 to 10.

In the alkane diol purification method according to an embodiment of the present invention, the buffer solution may be a mixed solution of sodium borate and sodium hydroxide.

In the alkane diol purification method according to an embodiment of the present invention, the sodium borate to be mixed in the buffer solution treatment step may be 0.5 to 10 parts by weight based on 100 parts by weight of the crude alkane diol.

In the alkane diol purification method according to an embodiment of the present invention, the activated carbon mixed in the deodorization step may be 1 to 10 parts by weight based on 100 parts by weight of the crude alkane diol.

The alkane diol purification method according to an embodiment of the present invention may further include a distillation step of removing water before the deodorization step after the buffer solution treatment step.

In the method of purifying an alkane diol according to an embodiment of the present invention, the alkane diol may be a 1,2-alkane diol having 5 to 8 carbon atoms.

The present invention relates to a method for treating a borate buffer solution; Activated carbon deodorization step; And a purified water treatment step. In this way, the alkane diol can be purified so that unpleasant odor is hardly generated.

1 is a graph showing the purity of 1,2-hexanediol purified by the method according to an embodiment of the present invention after measurement by gas chromatography.

Hereinafter, the method for purifying alkane diol according to the present invention will be described in detail. Here, unless otherwise defined, technical terms and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. In the following description, the gist of the present invention is unnecessarily blurred And a description of the known function and configuration will be omitted.

The present invention relates to a process for the preparation of a crude alkaline diol, comprising: a buffer solution treatment step of mixing a crude alkane diol and a borate buffer solution;

A deodorization step of deodorizing by adding activated carbon after the buffer solution treatment step; And

And a purified water treatment step of mixing the crude alkane diol having passed through the deodorization step with purified water.

When the alkane diol is purified by the method according to the present invention, there is an advantage that the alkane diol having little off-odor can be purified by a relatively simple method. Conventional alkanediol has antibacterial and moisturizing effect and is known as a useful substance in daily necessities such as cosmetics. However, when it is difficult to purify it and it is highly purified to remove bad odor or to remove odor, refining cost is too high There was a problem. However, when the alkane diol is purified by the method according to the present invention, it is advantageous to produce a purified alkane diol substantially free from offensive odor without requiring an excessive step or cost for the purification. Specifically, when the alkane diol is purified using a known carbonic acid buffer solution, a specific odor of the alkane diol may disappear, but there is a problem that a separate odor is generated by the addition of the carbonate. However, when the purification of the alkane diol is carried out in the same manner as in the present invention, not only the odor peculiar to the alkane diol is eliminated, but also the problem that other odors are mixed in the purification process can be prevented.

The method for purifying an alkane diol according to the present invention includes a buffer solution processing step of mixing a crude alkane diol and a borate buffer solution. In the present invention, the crude alkanediol may specifically be a 1,2-alkanediol having 5 to 8 carbon atoms, and more specifically 1,2-hexanediol, but the present invention is not limited thereto.

The pH of the borate buffer solution according to the present invention may be 9 to 10, preferably 9.3 to 10. The base component remains in the purified alkane diol finally while removing the odor of the alkane diol efficiently within the above-mentioned range, so that there is no problem in mixing with cosmetics in the future. More specifically, the borate buffer solution according to one embodiment of the present invention may be a mixed solution that satisfies the above-described pH range and is a mixture of sodium borate and sodium hydroxide. In the method of purifying an alkane diol according to an embodiment of the present invention, when the buffer solution treatment step is carried out with a mixed solution of sodium borate and sodium hydroxide, impurities contained in the crude alkane diol are efficiently removed, The buffer solution is mixed with the purified alkane diol in a minute amount so that odor other than the odor specific to the alkane diol is not generated.

The sodium borate to be mixed in the buffer solution treatment step according to an embodiment of the present invention may be 0.5 to 10 parts by weight, more specifically 0.5 to 3 parts by weight, per 100 parts by weight of the crude alkane diol. In the above-mentioned range, it is possible to efficiently remove the odor of the alkane diol, but not to affect the physical properties of the alkane diol due to the residual sodium borate. In addition, the amount of sodium hydroxide to be mixed in the buffer solution treatment step may be added to adjust the pH of the buffer solution to 9 to 10, preferably 9.3 to 10. Further, the solvent of the buffer solution containing sodium borate and sodium hydroxide may be water, and the amount of water to be mixed is not limited as long as the amount of water to be mixed with the alkane diol can separate the impurities. Specifically, The weight ratio of water may be 1: 0.5 to 5, more specifically 1: 0.8 to 3, but the present invention is not limited thereto.

In addition, this buffer solution treatment step can separate the impurities contained in the crude alkanediol by mixing the crude alkanediol with the borate buffer solution and stirring for 30 minutes to 10 hours, more specifically 1 to 4 hours.

Further, the step of treating the buffer solution according to an embodiment of the present invention includes a first buffer solution treatment step of treating the crude alkanediols in a pH range of 9.0 to 9.4; And a second buffer solution treatment step of treating the crude alkanediol in a pH range of 9.5 to 10.0. In the method of purifying an alkane diol according to an embodiment of the present invention, when the buffer solution treatment step is divided into two steps as described above, when the buffer solution having the same pH is treated twice, There is an advantage that the odor can be removed with a remarkably high efficiency.

The method of purifying alkane diol according to an embodiment of the present invention may further include a step of removing a part of water contained in the buffer solution before the deodorization step after the buffer solution treatment step. Specifically, this distillation step may be a step of removing 80 to 95% of the mixed water in the buffer solution treatment step described above. This distillation step may be carried out at a reduced pressure of 80 to 300 mmHg, but the present invention is not limited thereto.

Further, the method of purifying alkane diol according to an embodiment of the present invention may further include a fractional distillation step of fractionating the mixed solution containing alkane diol after the above-mentioned distillation step. Through this fractional distillation, the main liquid containing the alkane diol can be separated. In this case, the fractional distillation is not limited as long as the distillation can remove the water contained in the mixture. In a specific and non-limiting example, fractional distillation may be carried out at a pressure of 1 to 50 mmHg and a temperature of 75 to 110 DEG C, but the present invention is not limited thereto.

The method for purifying alkane diol according to the present invention comprises a deodorization step of deodorizing by adding activated carbon after the buffer solution treatment step. The method of purifying alkane diol according to the present invention includes deodorization step in which activated carbon is separately treated after the buffer solution treatment as described above, whereby impurities contained in the alkane diol can be removed with higher efficiency. Specifically, the method for purifying an alkane diol according to the present invention comprises a step of treating a buffer solution for treating a crude alkane diol with a borate buffer solution, and a deodorization step for treating activated carbon, thereby obtaining a purified alkane diol having a purity of 99.5% Can be prepared.

At this time, the activated carbon contained in the deodorization step may be 1 to 10 parts by weight, more specifically 2 to 7 parts by weight, relative to 100 parts by weight of the alkane diol. In the above-mentioned range, the deodorization process can be efficiently performed even if the filtration step for separating the activated carbon is not necessary for a long time. Furthermore, this deodorization step can be performed by adding activated carbon after the buffer solution treatment step and stirring for 1 to 10 hours, more specifically for 2 to 4 hours. The odor contained in the alkane diol can be removed as much as possible without requiring an excessive time for deodorization in the above-mentioned range.

In addition, this deodorization step can be carried out at 40 to 80 캜, specifically at 50 to 70 캜. The yield of the alkane diol can be further improved by preventing the evaporation of the alkane diol at an excessively high temperature while maximizing the deodorization efficiency in the above range.

More specifically, the deodorization step according to an embodiment of the present invention may be performed by mixing 0.5 to 5 times of purified water with the alkane diol together with the activated carbon in the above-described range. After the deodorization step and the fractional distillation step . Here, the distillation step and the fractional distillation step may be carried out in the same or similar manner to the distillation and fractional distillation steps performed after the buffer solution treatment step described above, but the present invention is not limited thereto.

The method for purifying an alkane diol according to the present invention includes a purified water treatment step of mixing a crude alkane diol having passed through deodorization step with purified water. Specifically, in the purified water treatment step, purified water having a weight of 0.5 to 5 times, more specifically 1 to 3 times the weight of the untreated alkanediol added is added and mixed, and the mixture is distilled and fractionally distilled to finally obtain high purity hexanediol can do.

Hereinafter, the present invention will be described in detail with reference to examples. The embodiments described below are only for the understanding of the invention, and the present invention is not limited to the embodiments.

[Example 1]

To 500 g of 1,2-hexanediol having severe odor, 750 g of purified water was put into a 2L four-necked flask, and 3.4 g of borax and pH of 9.7 were adjusted with caustic soda buffer solution, followed by stirring at room temperature for 1 hour. Thereafter, the temperature of the reactor was increased to evaporate about 720 g of water first under a reduced pressure of 100 mmHg, and thereafter, a vacuum distillation was performed at a reduced pressure of 5 mmHg and a temperature of 80 ° C to obtain 1,2-hexanediol- 1 main stream was separated, and the first main stream was about 465 g.

400 g of the first main stream and 600 g of purified water were placed in a 2 L four-necked flask, and 12 g of powdered activated carbon was placed in the flask, followed by stirring at 60 ° C. for 2 hours. Thereafter, the filtrate was filtered with a filter paper using diatomaceous earth to remove the activated carbon, and the filtrate was evaporated at a pressure of 5 mmHg and a fractional distillation at 90 ° C to obtain 1,2-hexanediol ≪ / RTI > was obtained.

360 g of the second main liquid and an equal amount of purified water were mixed and the water was evaporated to about 340 g under a reduced pressure of 100 mmHg and then washed with excess water at a reduced pressure of 5 mmHg and a temperature of 90 ° C and 1,2- The inlaid solution was removed and cooled to obtain 342 g of 1,2-hexanediol of high purity.

[Example 2]

750 g of purified water was added to 500 g of 1,2-hexanediol with severe odor in a 2 L four-necked flask, and the pH of the crude solution was adjusted to 9.3 with borax and caustic soda buffer, After stirring for 30 minutes, sodium hydroxide was further added to adjust the pH to 9.7, and the mixture was stirred at room temperature for 30 minutes. Under reduced pressure of 5 mmHg and distillation under reduced pressure at 80 DEG C, 1,2-hexanediol To separate the first main stream. Thereafter, the second mainstream liquid was obtained and the step of obtaining high purity 1,2-hexanediol was carried out in the same manner as in Example 1. [ The high-purity 1,2-hexanediol thus obtained was 340 g.

[Comparative Example 1]

In Example 1, the first main stream was taken and tested with purified alkanediol.

[Comparative Example 2]

After adding 750 g of purified water to 500 g of 1,2-hexanediol having a severe odor, 15 g of powdered activated carbon was added thereto, followed by stirring at 60 ° C for 2 hours for deodorization. The filtrate was distilled under a reduced pressure of 100 mmHg After evaporating about 720 g, the distillate was fractionally distilled at a temperature of 5 mmHg and 90 ° C to take the main liquid, which was then used as a purified alkane diol.

[Comparative Example 3]

Experiments were carried out on 1,2-hexanediol with severe odor without performing a separate purification step.

[Comparative Example 4]

To 500 g of 1,2-hexanediol having severe odor, 750 g of purified water was put into a 2 L four-necked flask, and 0.4 g of sodium hydrogencarbonate and 0.08 g of sodium carbonate were added to adjust the pH to 9.5, followed by stirring at room temperature for 1 hour. Thereafter, the process was carried out in the same manner as in Example 1.

Sensory evaluation of alkanediol odor

Each of the 10 samples of the alkanediol according to the examples and the comparative examples was subjected to the smell of each sample at intervals of 5 minutes, and the scores were given based on the following five points scale, Respectively.

1 point: odorless

2 points: barely detectable odor

3 points: Weak smell to know what smell

4 points: Easily detectable smell

5 points: strong smell

Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Sensory evaluation result 1.2 1.1 2.7 3.2 4 1.5

Referring to Table 1, in the case of 1,2-hexanediol according to an embodiment of the present invention, deodorization was performed to such an extent that almost no odor could be detected, but it can be confirmed that the comparative example is not. In addition, in the case of Comparative Example 4, in addition to a part of the characteristic odor of the conventional alkanediol, the evaluator partially sensed the odor felt by the evaluator, and it was confirmed that other odor causing substances were added during the refining process.

The purity determination of the alkanediol prepared in Example 1

The alkanediol purified in Example 1 was measured by Agilent 6890N gas chromatography under the condition of column HP-1, 30 m, 100% dimethylpolysiloxane and is shown in FIG. 1, and referring to FIG. 1, It can be confirmed that the purity of the purified 1,2-hexanediol is 99.81%.

Claims (7)

A buffer solution processing step of mixing the crude alkane diol and the borate buffer solution;
A deodorization step of deodorizing by adding activated carbon after the buffer solution treatment step; And
And a purified water treatment step of mixing the crude alkanediol via the deodorization step with purified water. The method according to claim 1,
Wherein the pH of the borate buffer solution is 9 to 10. 3. The method of claim 2,
Wherein the buffer solution is a mixed solution of sodium borate and sodium hydroxide. The method of claim 3,
The sodium borate mixed in the buffer solution treatment step is 0.5 to 10 parts by weight based on 100 parts by weight of the crude alkane diol. The method according to claim 1,
Wherein the activated carbon mixed in the deodorization step is 1 to 10 parts by weight relative to 100 parts by weight of the crude alkanediol. The method according to claim 1,
And a distillation step of removing water before the deodorization step after the buffer solution treatment step. The method according to claim 1,
Wherein the alkane diol is a 1,2-alkane diol having 5 to 8 carbon atoms.

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