KR20080007941A - Manufacturing method of high purity sorbitan - Google Patents

Abstract

A method for preparing 1,4-sorbitan is provided to obtain the 1,4-sorbitan with higher purity and excellent external appearance compared to currently available commercial products, thereby being used for preparing an agricultural film with high quality. A method for preparing 1,4-sorbitan comprises a step of reacting sorbitol with 0.1-2 wt.% of at least one acid catalyst selected from the group consisting of p-toluene sulfonic acid and H3PO2 at a temperature of 110-135 deg.C under the pressure of 40-120 torr for 1-20 hours.

Description

The Preparation Method of 1,4-Sorbitan With High Purity

1 is a graph showing the results of the synthesis of 1,4-sorbitan prepared in the laboratory by the method of the present invention.

Figure 2 is a graph showing the synthesis results of 1,4-sorbitan prepared in a pilot experiment by the method of the present invention.

Figure 3 is a graph showing the synthesis results of 1,4-sorbitan prepared in a pilot experiment by the method of the present invention.

Figure 4 is a graph showing the results of the synthesis of 1,4-sorbitan prepared in the plant experiment by the method of the present invention.

Figure 5 is a photograph comparing the appearance color of 1,4-sorbitan and Japanese centralized product produced in the plant experiment by the method of the present invention.

Figure 6 is a graph showing the synthesis results of 1,4-sorbitan prepared at 145 ℃, 460torr conditions.

Figure 7 is a photograph comparing the appearance color of 1,4-sorbitan and Japan Centralized Products produced at 145 ℃, 460torr conditions.

The present invention relates to a manufacturing method of sorbitan (Sorbitan), and more particularly, to provide a method for producing 1,4-sorbitan in high purity.

When packaging or hot-bed coating of foods with PE, EVA and PVC films, water droplets form on the inner surface of the film, which adversely affects food storage and crop growth. In order to improve this, the AF (Antifogging) agent, which is a kind of nonionic surfactant, is added to increase the surface tension of the plastic film to improve affinity with water. In particular, the use as an additive for hot-phase film is prominent because it is consumed while the AF agent is spreading and flowing water droplets generated by contact with the film surface. Consumption of the AF agent has a strong relationship with the film material material compatibility, the temperature around the hotbed and the vapor evaporation amount inside the hotbed, and thus it is very difficult to maintain a constant invincibility.

The most commonly used substance among these AF agents is Span (Sorbitan monofatty acid ester) family. Sugar fatty acid ester, in which the hydroxyl group of the sugar molecule is acylated with the carboxyl group of the fatty acid to form an ester bond, can be used as a surfactant and additive for various uses, including food and pharmaceuticals. Dividing by various three-dimensional coupling methods, it is possible to use optical materials and biological fields in the field of external engineering requiring high functional composite materials. Synthesis of sorbitan fatty acid esters using sorbitol, a sugar alcohol, produces by-products, resulting in a mixture of mono-, di- and tri-fatty acid esters. This results in frequent claims from farmers because the data of invincible initial, invincible persistence, and invincible low temperature in film are inconsistent.

In general, the manufacturing process of sorbitol is mixed with sorbitol and fatty acid and dehydrated at a high temperature of about 230 ° C. to produce sorbitan. The conversion to sorbitan is very difficult to exceed 50%, and is generally about 40%. . The catalyst is added thereto to prepare a span.

Accordingly, it is an object of the present invention to provide a method for producing high purity 1,4-sorbitan.

Another object of the present invention is to synthesize Span with high purity 1,4-sorbitan to improve the quality of agricultural films.

The object of the present invention is to add 0.1-2% by weight of at least one acid catalyst selected from sorbitol with p-toluenesulfonic acid and H ₃ PO ₂ , at a reaction temperature of 110-135 ° C. at a pressure of 40-120 torr. It is achieved by the method for producing 1,4-sorbitan consisting of reacting for 20 hours.

The temperature is faster than 135 ℃ reaction rate is fast but promotes the carbonization of the product has a bad effect on the overall color and less than 110 ℃ 110-135 ℃, especially 110-120 ℃ is preferable because the reaction does not occur well.

The lower the pressure, the lower the reaction temperature to improve the quality of the product, but the reaction rate is slow, so 40 to 120 torr is preferable.

Purity of 1,4-sorbitan prepared by the production method of the present invention is 85% or more, the yield is 90% or more.

The present invention will be described in more detail with reference to the following Examples.

Example 1

1 kg of sorbitol was placed in a four neck flask and heated to about 100 ° C. After melting was complete, 0.2% of a p-toluenesulfonic acid and H ₃ PO ₂ mixed catalyst was added. The temperature was raised to 125 ° C. and vacuum was applied to adjust the pressure to 120 torr. The results are shown in FIG.

Purity 1,4- sorbitan of more than 85% was obtained, the color was also very stable.

Example 2

6 kg of sorbitol was placed in a pilot device made of SUS 304 and heated to about 100 ° C. After melting was complete, 0.2% of a p-toluenesulfonic acid and H ₃ PO ₂ mixed catalyst was added. The temperature was raised to 123 ° C. and vacuum was applied to adjust the pressure to 110 torr. The results are shown in FIG.

The reaction was best after 5 hours. Purity 1,4- sorbitan of more than 85% was obtained, the color was also very stable.

Example 3

60 kg of sorbitol was placed in a pilot device made of SUS 304 and heated to about 100 ° C. After melting was complete, 0.2% of a p-toluenesulfonic acid and H ₃ PO ₂ mixed catalyst was added. The temperature was raised to 125 ° C. and vacuum was applied to adjust the pressure to 40 torr. The results are shown in FIG.

The reaction rate is 10 times larger than that of Example 2, but the reaction rate is not much different. This is the result of the reaction under reduced pressure about 70torr. Both purity and color were good.

Example 4

1500 kg of sorbitol was placed in a plant device made of SUS 316L and heated up to about 100 ° C. After melting was complete, 0.2% of a p-toluenesulfonic acid and H ₃ PO ₂ mixed catalyst was added. The temperature was raised to 115 ° C. and vacuum was applied to adjust the pressure to 45 torr. The results are shown in FIGS. 4 and 5.

The yield was 90.2%, purity was 87.65%, and color was the best.

The results of comparing the quality with the commercially available products of Central Japan of Japan are published in Table 1 below.

Table 1

Evaluation Items (Major Performance Spec ¹⁾ ) unit Japan Central Mars Products Product Development Goal Performance (%) Evaluation method ³⁾ 1. Appearance Light yellow Light yellow 100 Visual inspection 2.pH 3.5 to 4.5 4 100 pH meter 3.viscosity (25 ℃, 70% soln.) cps 1,000-2,000 1,100 100 BROOKFIELD Viscometer No. 7 4.Sorbitol % 5 or less 2.35 100 Gas chromatography 5.Sorbitan % 80 or more 87.65 100 Gas chromatography 6.Sorbide % below 10 10 100 Gas chromatography

Comparative Example 1

The reaction was carried out in the same manner as in Example 1, but the reaction was performed at 145 ° C. and 460 torr. The results are posted in FIGS. 6 and 7.

Purity and yield were good, but there was a problem with the color brown as shown in FIG.

According to the manufacturing method of the present invention, it is possible to produce 1,4-sorbitan having a higher purity and better appearance than commercially available products. Therefore, high-purity span production is also possible to provide a high quality agricultural film.

Claims (4)

Sorbitol is added by adding 0.1-2% by weight of at least one acid catalyst selected from p-toluenesulfonic acid and H ₃ PO ₂ , and reacting at a reaction temperature of 110-135 ° C. at a pressure of 40 to 120 torr for 1 to 20 hours. Method for producing 1,4-sorbitan. The method of claim 1, wherein the pressure is 40-60 torr. The method of claim 1, wherein the reaction temperature is 110-120 ° C. The method of claim 1, wherein the catalyst is a mixed catalyst of p-toluenesulfonic acid and H ₃ PO ₂ .

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