KR19990018543A - Manufacturing method of polyolefin hollow fiber membrane - Google Patents

Abstract

The present invention relates to a process for producing a hollow fiber membrane based on a polyolefin-based material, and has an object of producing a polyolefin-based hollow fiber membrane having a uniform and uniform pore and can be used continuously.

Specifically, the present invention transfers a mixture of a bicomponent single phase consisting of a polyolefin-based polymer and dibutyl phthalate, which is a porous body, to a spinneret to spin in the presence of a hollow body, and the hollow fiber formed thereafter passes through a discharge part having a temperature gradient and a driving roll. The method for producing a polyolefin hollow fiber separator characterized in that it is quenched through a coagulating solution, and the formed hollow fiber is removed using a extractant and then wound using a reel winder. A hollow fiber separator is obtained which has a uniform and uniform pore and can be used continuously.

Description

Method for producing polyolefin hollow fiber separator

The present invention relates to a process for producing a hollow fiber membrane based on a polyolefin-based material, and more particularly, to a method for manufacturing a polyolefin-based hollow fiber membrane having a uniform and uniform pore, which can be used continuously.

Membrane separation process has not been regarded as a technically important separation process, but the interest and research and development have been increasing recently as the membrane separation process has been used for many applications. As a filtration method used in such membrane separation process, Microfiltration, ultrafiltration, reverse osmosis, gas separation, pervaporation, and so on.

In general, microfiltration membranes having a pore size of 0.05 to 10 μm and suitable for concentrating suspensions or emulsions are most widely used in various industries including medicine and fermentation as membranes most closely related to existing filtration methods. These microfiltration membranes are currently manufactured in the form of hollow fibers by thermally induced phase separation (TIPS) and cold stretching methods. The latter forms pores by drawing, so the final hollow fiber separator has very low elongation. There is a shortcoming in the lack of flexibility with respect to the pressure during air cleaning for repeated use. In contrast, the electrons are manufactured in a state in which the hollow yarn is hardly drawn. First, two different components are heated to a constant temperature to form a single phase, and then spun at an appropriate temperature, and then the spun hollow fiber is a desired temperature again. After forming the microporous surface by quenching with water, the porous form is removed using an extractant, so it is possible to manufacture high-strength hollow fiber membranes that can withstand the air cleaning pressure during the cleaning process. Since the use time of the filtration membrane can be significantly increased, the situation has been widely studied in recent years as a hollow fiber membrane production method.

As such, a method for manufacturing a hollow fiber membrane having a high elongation after washing for a predetermined time is known from US Patent 4,594,207, US Patent 5,250,240, US Patent 5,395,570, and the like. However, these methods perform spinning under high temperature spinning process conditions in order to control the radioactive and phase separation behavior during spinning process that influences the properties of the hollow yarn, and then fine porosity through phase separation behavior during solidification and cooling of the spun fiber. In order to obtain a surface, it is solidified and cooled with air or oil, etc. At this time, the surface becomes uneven due to contact with oil, a third component or air, and foreign matter remains on the surface during final hollow fiber formation. Due to such a problem, there is a possibility that the performance of the hollow fiber membrane filter is deteriorated and a problem such as contamination occurs during the production of pure water. In addition, the component that causes phase separation behavior as a microporous body has the advantage of low price and easy handling when using oil, but general edible oil has a problem that tends to be burned at high temperatures because of poor thermal stability.

Accordingly, in order to prevent oxidation and to solidify the hollow fiber at the proper temperature condition, a vacuum unit with a heating device should be installed between the spinneret and the coagulating liquid. It is very important that such a vacuum has a temperature gradient to a certain length, because the performance of the hollow fiber membrane is determined by the temperature difference according to each part. The first region is a region in which phase separation behavior occurs, so that the degree of phase separation of the two components is adjusted to have a uniform and appropriate size for the hollow fiber, so the temperature of this region determines the separation performance of the hollow fiber membrane. The second region is a region that forms the fiber structure of the hollow fiber membrane, and in order to obtain a good separation performance of the hollow fiber membrane after the phase separation, it is preferable that the porous structure forms a fibrillated structure. Through spontaneous stretching through this fibril structure. The third region is a region for controlling the physical properties of the formed hollow yarns, and complete cooling in the third region to maintain the shape of the hollow yarns. If this part is not fully cooled, it is difficult to have a fibril structure in the second region.

Since the hollow fiber membrane obtained by the above method has high elongation, high porosity and a porous surface, the surface has a very soft feature. There is a problem that the circular retention rate is lowered and damage to the dead surface is likely to occur.

The present invention has been made to solve the above problems, the object of the present invention is to provide a method for producing a polyolefin-based hollow fiber membranes suitable for use in the method of directly cutting without the sea process.

The present invention is a method for achieving the above object by heating a mixture consisting of a polyolefin-based polymer and dibutyl phthalate, a porous component having excellent extraction efficiency and excellent thermal stability to form a single phase and transported to a spinneret It spins in the presence of a hollow body, and then passes through a discharge section having a temperature gradient of 1 m or more, and then quenchs through a coagulating liquid through a driving roll that maintains a stable tension of the hollow fiber membrane. It provides a method for producing a polyolefin hollow fiber membrane, characterized in that it is immersed in the extraction tank containing the extractant for several seconds in order to remove the wound using a winder.

As the polyolefin-based polymer used in the present invention, polypropylene is mainly used, and it is preferable to use hot nitrogen gas to serve as a hollow body during spinning at the spinneret and to maintain the temperature of the spinneret part. .

In addition, the spinning temperature of the spinneret is suitable in the range of 160 ~ 200 ℃, if the spinning temperature exceeds 200 ℃, the carbonization of the porous body is likely to occur, the physical properties of the polyolefin is deteriorated, the spinning temperature is 160 If the temperature is less than 0 ° C., the spinneret may be clogged and the discharge may not be easily performed.

The discharge portion used in the present invention is advantageously configured to have a temperature gradient in the temperature range of about 50 ~ 200 ℃ more than 1m, and thus by using an discharge portion having a length of 1m or more between the spinneret and the coagulation liquid Promote the formation of microporous surfaces. In addition, in the present invention, it is more preferable to use a roll capable of driving a coagulating solution bath to protect the cross section of the hollow yarn during winding of the manufactured hollow yarn by forming a middle speed gradient between the spinning speed and the winding speed.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples.

(Example 1)

Polypropylene (Mw: 400,000) was used as a polyolefin-based polymer and dibutyl phthalate was used as a porous body to form a single-phase liquid, followed by melt spinning in a hollow fiber form at 200 ° C. using hot nitrogen gas as a hollow body. At this time, it passed through the discharge part of the length of 1.5m gave a temperature gradient in three steps from 200 ℃, and the spun hollow yarn passed through the driving roll and passed through the coagulation tank and the extraction tank composed of a known structure and components through the winder It was wound up, and the physical properties thereof were shown in Table 1.

(Example 2)

Except that the discharge portion to 1.8m was carried out in the same manner as in Example 1, the physical properties were evaluated and the results are shown in Table 1.

(Example 3)

Except that the discharge portion was set to 2.0m was carried out in the same manner as in Example 1, the physical properties were evaluated and the results are shown in Table 1.

Comparative Example 1

Except that the length of the discharge portion 0.4m was carried out in the same manner as in Example 1, the physical properties were evaluated and the results are shown in Table 1.

Comparative Example 2

In Example 1 was carried out in the same manner as in Example 1 except that the driving roll was not passed, the physical properties were evaluated and the results are shown in Table 1.

Comparative Example 3

The discharge was carried out in the same manner as in Example 1 except that the temperature was set to 100 ° C without a temperature gradient, and the physical properties were evaluated and the results are shown in Table 1.

Property classification Tensile Strength (g / ㎠) Elongation (%) Uniformity (%) Circular retention rate (%) Cut off (time) Example 1 3.0 200 99 99.9 0 Example 2 2.4 191 98 99.9 One Example 3 2.5 183 98 99.8 0 Comparative Example 1 0.8 382 91 96.0 0 Comparative Example 2 2.3 167 72 84.1 6 Comparative Example 3 2.2 92 99 94.0 12

As can be seen in the above examples and comparative examples, the hollow fiber prepared according to the present invention has excellent properties such as being able to use continuously while having excellent uniformity and uniform porosity while having excellent physical properties such as tensile strength and elongation.

Claims (5)

This component mixture, consisting of a polyolefin-based polymer and dibutyl phthalate, which is a porous body, is heated to form a single phase, transferred to a spinneret, and spun in the presence of a hollow body, and then passed through an outlet having a temperature gradient of 1.5 m or more, followed by hollow fiber Polyolefin-based hollow fiber, characterized in that it is quenched through a coagulating solution through a driving roll to maintain a stable tension of the separation membrane, the porous fiber formed in this way to remove the porous form using an extractant, and then wound using a winder Method for producing a separator. The method of claim 1, wherein the spinning temperature of the spinneret is controlled in a range of 160 to 200 ℃. The method of manufacturing a polyolefin-based hollow fiber membrane according to claim 1, wherein hot nitrogen gas is used as the hollow body. The method of claim 1, wherein the discharge portion has a temperature gradient in the range of 50 to 200 ° C. The method of claim 1, wherein the polyolefin-based polymer is polypropylene.