KR101984059B1 - Manufacturing method of polyketone porous membrane, polyketone porous membrane and polyketone flat sheet type membrane manufactured using the same - Google Patents

Abstract

A method for manufacturing a porous polyketone membrane according to the present invention comprises the steps of: mixing polyketone and a diluent at a temperature of 190-270°C to manufacture a dope solution; applying the manufactured dope solution on a support, rapidly solidifying the solution using an aqueous coolant containing at least one selected from a group consisting of water and an organic solvent at 4-70°C, and manufacturing a porous polyketone membrane by a heat-induced separation method; and extracting and removing the diluent from the porous membrane. According to the present invention, a porous polyketone membrane excellent in chemical resistance and heat resistance can be manufactured.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a porous film of polyketone, a porous film of polyketone prepared by the method, and a membrane of polyketone,

The present invention relates to a process for producing a porous film of polyketone, and a polyketone porous membrane and a polyketone flat membrane prepared using the same.

One of the most widely used methods for producing polymer membranes is the non-solvent induced phase separation method. The non-solvent-derived phase separation method is a method of preparing a separation membrane by a solvent-non-solvent interchange by carrying a dope solution prepared by dissolving a polymer in a strong organic solvent, It is difficult to control the pore of the separation membrane and the three-dimensional structure of the separation membrane to some extent.

In addition, since a polymer having a high number-average molecular weight has a critical point to be dissolved in a solvent, a polymer having a high number-average molecular weight and a polymer membrane produced without increasing the concentration of the polymer may have a low mechanical strength .

Recently, attention has been focused on a separation membrane called an organic solvent nanofiltration or an organic solvent resistant nanofiltration or an organic solvent resistant membrane and a process for producing the same, Is a membrane technology that has been attracting attention in a very wide range of separation processes such as refining, chemical, pharmaceutical, catalyst, and food industries where synthesis and purification separation are performed within the membrane. The above technology has recently been undergoing many studies with advantages of lower energy and lower cost than conventional methods such as evaporation or absorption. However, unlike general polymer membranes for water treatment, organic solvent nanoparticles are resistant to chemicals in solvents such as ethanol, methanol, toluene, acetone, dimethylacetamide, dimethylsulfoxide, dimethylformamide or N-methylpyrrolidone, The permeability and stability against long-term operation must be secured.

On the other hand, polyketone is one of polyolefin-based polymers having excellent mechanical strength, chemical resistance and heat resistance. It is a polymer material attracting attention as a material of separation membrane applicable to special separation process using not only engineering material parts but also organic solvent , It is somewhat difficult to dissolve even in a strong solvent, so its utilization is limited.

Korean Patent Publication Nos. 2017-0087240, 2015-0033424 and Korean Patent No. 1734894 disclose a process for producing a flat membrane or a hollow fiber membrane using a polyketone polymer and a polyketone membrane produced by the above process, . The polyketone separator prepared by the above process uses a conventional non-solvent-derived phase separation method. However, since there is almost no organic solvent capable of dissolving the polyketone polymer, the polyketone separator is prepared by adding hexafluoroisopropanol, zinc chloride (ZnCl ₂ ) CaCl ₂ ), and lithium chloride (LiCl), to prepare a separator. However, since the solubility of the polyketone polymer in the aqueous solution of the metal salt other than the organic solvent is very limited, the weight percentage of the polyketone polymer in the aqueous solution does not exceed 2 to 10 wt%, which is a major cause of weakening the mechanical strength of the separator .

U.S. Published Patent Application No. 2017-0157567 discloses a method for producing an organic solvent nanoparticle by using a non-solvent-derived phase separation method such as polyimide or polybenzimidazole, which is excellent in chemical resistance and heat resistance, A separator is produced. However, since the prepared membrane still has the disadvantage of being dissolved in a strong organic solvent, a complicated additional process which causes a crosslinking reaction by adding a crosslinking agent for a long time is performed in order to solve this problem.

Therefore, even if an additional crosslinking reaction or a post-treatment step is not carried out, there is a need to develop a method for producing a separator which is excellent in chemical resistance, solvent permeability and stability against long-term operation and excellent in mechanical strength.

Korean Patent Publication No. 2017-0087240 (Jul. 27, 2017) Korean Patent Publication No. 2015-0033424 (2015.04.01.) Korean Patent No. 1734894 (Apr. U.S. Published Patent Application No. 2017-0157567 (Jun.

Disclosed is a polyketone porous membrane having chemical resistance and heat resistance in a separating membrane process using a strong organic solvent as a raw solution and a method for producing the same, which solve the disadvantages of conventional polyketone flat membrane type or hollow fiber membrane.

It is another object of the present invention to provide a method for producing a polyketone porous membrane which can replace conventional processes which are complicated and have a large amount of pollutant emissions, using a metal salt aqueous solution because they can not be produced by the conventional non-solvent-derived phase separation method.

The present invention relates to a process for producing a dope solution by heating a mixture of a polyketone and a diluent to melt the polyketone to prepare a dope solution; Applying the dope solution on a support, solidifying the aqueous solution using an aqueous coolant containing at least one selected from the group consisting of water and an organic solvent to produce a polyketone porous membrane; And removing the diluent from the porous membrane. The present invention also provides a method for producing a porous film of polyketone.

The present invention also provides a polyketone porous film produced by the above-described method for producing a porous film of polyketone.

The present invention also provides a polyketone flat membrane separator comprising the above-described polyketone porous membrane.

The present invention has an advantage that a polyketone porous membrane having excellent chemical resistance and heat resistance can be produced by using a heat-induced phase separation method.

Further, the present invention is advantageous in that it is economically advantageous to use a relatively inexpensive diluent without using a strong organic solvent or a metal salt.

In addition, the polyketone porous membrane and the polyketone flat membrane type membrane produced according to the present invention have an advantage of excellent mechanical strength because they are produced using a high content of polyketone.

Fig. 1 is an electron micrograph (magnification = 1,000 times) of a section of a polyketone porous membrane prepared according to Example 1. Fig.
2 is a scanning electron micrograph (magnification = 5,000 times) of the surface of the polyketone porous membrane prepared according to Example 1. Fig.
3 is an electron micrograph (magnification = 1,000 times) of the cross-section of the polyketone porous membrane produced according to Example 2. Fig.
4 is an electron micrograph (magnification = 5,000 times) of the surface of the polyketone porous membrane prepared according to Example 2. Fig.
5 is an electron micrograph (magnification = 1,000 times) of the cross section of the polyvinylidene fluoride porous membrane prepared according to Comparative Example 1. Fig.
6 is an electron micrograph (magnification = 5,000 times) of the surface of the polyvinylidene fluoride porous membrane produced according to Comparative Example 1. Fig.
7 is a graph showing the net water permeation amount of the porous membrane produced according to Examples 1 and 2 and Comparative Example 1. Fig.
8 is a graph showing the breaking strength and the tensile modulus of the porous membrane produced according to Examples 1 and 2 and Comparative Example 1. Fig.

Hereinafter, the present invention will be described in more detail.

When a member is " on " another member in the present invention, it includes not only a member directly contacting another member but also another member interposed between the two members.

Whenever a part is referred to as " including " an element in the present invention, it is to be understood that it may include other elements as well, without departing from the other elements unless specifically stated otherwise.

One aspect of the present invention is a process for producing a polyketone comprising the steps of: preparing a dope solution by heating a mixture of polyketone and a diluent to melt the polyketone; Applying the dope solution on a support, solidifying the aqueous solution using an aqueous coolant containing at least one selected from the group consisting of water and an organic solvent to produce a polyketone porous membrane; And removing the diluent from the porous membrane.

In the present invention, the term " porous film " means that the inside or the surface of the film includes pores and can be used in a sense commonly understood by those skilled in the art.

The diameter of the pores may be from several nanometers to several tens of micrometers, and the porosity of the porous structure may be 60 to 90%, but is not limited thereto. That is, the pores may be referred to as pores formed in the polyketone membrane itself, which is manufactured to a size of several nanometers to several tens of micrometers.

The polyketone is a linear alternating structure containing substantially carbon monoxide per molecule of unsaturated hydrocarbon. Ethylenically unsaturated hydrocarbons suitable for use as precursors of polyketones have up to 20, preferably up to 10, carbon atoms. Ethylenically unsaturated hydrocarbons can also be selected from the group consisting of ethene and alpha-olefins such as propene, 1-butene, iso-butene, 1- hexene, 1- octene, , Or an aryl aliphatic group containing an aryl substituent on another aliphatic molecule, particularly containing an aryl substituent on an ethylenically unsaturated carbon atom. Examples of aryl aliphatic hydrocarbons in ethylenically unsaturated hydrocarbons include styrene, p-methyl styrene, p-ethyl styrene and m-isopropyl styrene.

The polyketone preferably used in the present invention is a copolymer of carbon monoxide and ethene or a second ethylenically unsaturated hydrocarbon having carbon monoxide, ethene and at least three carbon atoms, in particular alpha-olefins such as propene, Of a terpolymer.

The polyketone used in the present invention may have a number average molecular weight (M _n ) of 100 to 200,000, preferably 10,000 to 200,000, more preferably 50,000 to 200,000, and particularly preferably 90,000 to 200,000. In this case The polyketone porous membrane to be produced is advantageous because it has an advantage of excellent mechanical strength.

The process for producing a polyketone porous membrane according to the present invention comprises the steps of heating a mixture of a polyketone and a diluent to melt the polyketone to prepare a dope solution.

In one embodiment of the present invention, the temperature at which the mixture of the polyketone and the diluent is heated may be a temperature below the boiling point of the aqueous refrigerant.

The melting point of the polyketone used in the present invention may be 175 to 300 占 폚, preferably 190 to 270 占 폚, more preferably 200 to 220 占 폚, and the temperature within the melting point of the polyketone, preferably 190 to 270 占 폚, Preferably at a high temperature of 200 to 220 DEG C, to prepare a dope solution in which a polyketone and a diluent are uniformly mixed and to prepare a separator.

Specifically, the temperature in the range of 200 to 220 ° C is higher than the melting point of the polyketone polymer, specifically, the melting point of the polyketone polymer which is slightly lowered due to the diluent, the boiling point of the polyketone polymer point of the polyketone porous membrane, and the polyketone porous membrane according to the present invention may be prepared by uniformly mixing the polyketone at the temperature within the above range and then lowering the temperature to solidify the polyketone.

The method for producing the polyketone is not limited thereto, but the method disclosed in U.S. Patent No. 4,843,144 may be used. For example, an anion of a dihydrohalogenic acid having a pKa of 6 or less, preferably of less than pKa 2 (18 Lt; 0 > C in water) and carbon monoxide and hydrocarbon monomer in the presence of a catalyst composition appropriately produced from the two-coordinate ligand of phosphorus under polymerization conditions.

In one embodiment of the present invention, the polyketone is contained in an amount of 10 to 50% by weight based on 100% by weight of the total dope solution; And 50 to 90% by weight of the diluent. Preferably, the polyketone may be contained in an amount of 15 to 45% by weight, more preferably 20 to 40% by weight, based on 100% by weight of the total dope solution, 85% by weight, more preferably 60 to 80% by weight.

When the polyketone and the diluent are contained within the above range, the polyketone porous membrane having excellent durability can be advantageously produced.

In order to prepare the polyketone porous membrane according to the present invention, firstly, 10 to 50% by weight of polyketone and 50 to 90% by weight of diluent are mixed at a temperature of preferably 190 to 270 캜, more preferably 200 to 220 캜, For a period of time to prepare a dope solution.

The diluent is not limited as long as it can lower the melting point of the polyketone and can finely and uniformly disperse the polyketone polymer at a high temperature.

In another embodiment of the present invention, the diluent is selected from the group consisting of dimethyl phthalate, dibutyl phthalate, dioctyl phthalate, r-butyrolactone, diethyl phthalate, Diethylene phthalate, propylene glycol, ethylene glycol, glycerol triacetate, diphenyl ketone, dibutyl sebacate and liquid paraffin. Or a mixture of two or more of them.

The preparation of the dope solution can be carried out through a high temperature mixer. Since the polyketone dope solution has a characteristic that phase separation occurs very rapidly due to a minute difference in temperature, the high temperature mixer for mixing the dope solution and the support The temperature should be maintained.

When preparing the dope solution through the high-temperature mixer, the interior of the high-temperature mixer may be replaced with an inert gas such as nitrogen, which is not reactive, if necessary, but is not limited thereto.

In still another embodiment of the present invention, the method may further include stirring the dope solution to remove bubbles in the dope solution. The step of stirring the dope solution is preferable because the mechanical strength of the produced polyketone porous film is further improved.

In another embodiment of the present invention, the step of stirring the dope solution may be carried out at a speed of 10 to 800 rpm for 1 to 12 hours. Preferably at a rate of 10 to 500 rpm, more preferably at a rate of 10 to 100 rpm, which is preferably maintained for 1 to 9 hours, more preferably for 1 to 3 hours to maintain the low- .

The method for producing a polyketone porous membrane according to the present invention is characterized in that the above-prepared dope solution is coated on a support and is rapidly cooled at a temperature of 4 to 70 캜 using an aqueous refrigerant containing at least one selected from the group consisting of water and an organic solvent And solidifying the polyketone porous membrane to produce a polyketone porous membrane by a heat-induced phase separation method.

The application of the dope solution onto the support may be performed by a method generally used in the art. For example, the application may be performed by a suitable method such as a die coater, an air knife, a reverse roll, a spray, a blade, a casting, a gravure, a micro gravure and a spin coating.

However, in the case of coating using the above-mentioned coating method, the equipment is heated at a temperature not lower than the melting point of the polyketone and not higher than the boiling point of the aqueous coolant of the polyketone polymer, preferably 200 to 220 ° C The temperature should be maintained.

Specifically, the coating is preferably performed using a flat film production apparatus using a blade, and the temperature of the knife and the glass plate or the Teflon plate for producing the polyketone flat film type separation membrane are preferably set such that the melting point of the polyketone , A temperature below the boiling point of the aqueous coolant of the polyketone polymer, preferably 200 to 220 ° C, should be maintained.

In another embodiment of the present invention, the rate at which the dope solution is applied is 1 m / min to 30 m / min, preferably 3 m / min to 25 m / min, more preferably 6 m / 15 m / min. When the application speed is within the above range, the dope solution is maintained in a uniform phase and the thickness of the separation membrane is advantageously uniform.

The rapid solidification may be carried out at a cooling rate of 0.1 ° C / sec to 250 ° C / sec, preferably 10 ° C / sec to 230 ° C / sec, more preferably 50 ° C / sec to 220 ° C / sec, It is advantageous in that a structure in which the cross section of the separation membrane has a net structure is obtained.

When the cross-section of the separator has a mesh structure, a separator film having better mechanical strength such as elongation can be obtained.

In another embodiment of the present invention, the support may comprise thermoplastic synthetic fibers.

The thermoplastic synthetic fibers may be, for example, polyamide, polyethylene, polyester, polyisobutylene, polytetrafluoroethylene, polypropylene, polyacrylonitrile, polysulfone, polyether sulfone, polycarbonate, polyethylene terephthalate, , Polyvinylene fluoride, polyvinyl chloride, cellulose acetate, cellulose diacetate, cellulose triacetate, and the like.

Preferably, the thermoplastic synthetic fiber may be polyethylene terephthalate, which is advantageous because it has an advantage of being excellent in resistance to an organic solvent.

In another embodiment of the present invention, the support may be a nonwoven or nanofiber web having a basis weight of 60 to 100 g / m ² _, preferably 70 to 100 g / m ² , more preferably 80 to 100 g / m ² .

When the basis weight of the support is within the above range, the coating solution is advantageously coated uniformly without penetrating into the support.

The method of producing the nonwoven fabric or the nanofiber web is not limited to the present invention. For example, the nonwoven fabric or the nanofiber web may be formed by forming nanostructured materials by block segments, forming nanostructured materials by self-assembly, forming nanofibers by polymerization under silica catalyst, forming nanofibers by carbonization after melt spinning, Or formation of nano-woven fabric by electrospinning of a melt, but the present invention is not limited thereto.

In another embodiment of the present invention, the thickness to which the dope solution is applied on the support may be 10 to 50 占 퐉, preferably 20 to 50 占 퐉, more preferably 30 to 50 占 퐉. When the thickness is within the above range, the strength of the separation membrane is not weak and the high permeability is maintained. The thickness is the thickness after application and after solidification.

The dope solution is coated on the support and rapidly solidified at a temperature of 4 to 70 ° C using an aqueous coolant containing at least one selected from the group consisting of water and an organic solvent to prepare a polyketone porous film by a heat induction phase separation method .

In another embodiment of the present invention, the temperature of the aqueous refrigerant may be 4 to 70 캜, preferably 10 to 40 캜, more preferably 20 to 30 캜. When the temperature of the aqueous refrigerant is within the above range, the cross-sectional structure of the separator has a net shape, which is preferable.

In another embodiment of the present invention, the organic solvent may be contained in an amount of 5 to 50% by weight, preferably 10 to 50% by weight, more preferably 30 to 50% by weight based on 100% by weight of the aqueous refrigerant .

In short, it is preferable that the aqueous refrigerant is a mixture of water and an organic solvent. In this case, it is preferable that the organic solvent is included in the above-mentioned range and water is included in the remainder.

When the above range is satisfied, it is preferable to appropriately increase the size of the membrane pores.

It is preferable that the organic solvent includes a water-soluble solvent since it is easy to separate and clean the refrigerant in the future. Specifically, the organic solvent may be water-soluble or water-soluble.

In yet another embodiment of the present invention, the organic solvent is selected from the group consisting of dibutyl phthalate, dioctyl phthalate, r-butyrolactone, diethyl phthalate, It is preferable to selectively mix one or more of propylene glycol, ethylene glycol, glycerol triacetate, polyethylene glycol, and glycerol.

In the case of polyolefin-based polymers such as polypropylene, polyethylene, polyethylene-chlorotrifluoroethylene, and polytetrafluoroethylene, general polymeric materials have a thermal property in melting in a strong organic solvent, Separation membranes are prepared by inductive separation.

The heat-induced phase separation method is a method in which a homogeneous single-phase dope solution is prepared by dispersing and mixing with a diluent at a temperature higher than the melting point of the molecule, and then subjected to shaping in the form of a flat membrane or hollow fiber membrane And cooling the heat to induce phase separation of the polymer and the diluent.

The solidified membrane is a method of preparing a final membrane by extracting a diluent remaining in the membrane using an appropriate extracting agent and then drying the membrane to obtain a polypropylene ), Polyethylene (polyethylene), and polyethylene-chlorotrifluoroethylene (PTFE).

In the present invention, since the heat-induced phase separation method is used, there is an advantage that a polyketone porous membrane can be produced which has a somewhat low solubility in a strong solvent and which is somewhat difficult to prepare as a separation membrane.

The polyketone having a high molecular weight can be used and the concentration of the polyketone in the produced polyketone porous membrane can be increased by 70 wt% or more, so that the mechanical strength is higher than that of the polymer membrane prepared by the conventional non-solvent- There is an advantage.

Specifically, the step of rapid solidification using an aqueous refrigerant and the production of a polyketone porous membrane by the heat-induced phase separation may be performed by rapidly immersing the membrane coated on the support in an aqueous refrigerant coagulant.

A method of making a polyketone porous membrane according to the present invention comprises the step of removing the diluent from the porous membrane.

Specifically, the polyketone porous membrane produced by the heat-induced phase separation method is solidified in an aqueous refrigerant and then carried on a washing tank containing pure water to extract the diluent and dry it at room temperature.

The method for producing a porous film of polyketone according to the present invention is a method for producing a polyketone porous film by a method in which a polyketone having excellent chemical resistance and heat resistance and a diluent capable of uniformly dispersing the polyketone are subjected to a heat- And the pores of the microfiltration or ultrafiltration membrane can be freely controlled through the mutual solvent reaction between the diluent and the aqueous refrigerant. Therefore, it is possible to manufacture porous membranes and membranes having excellent performance as compared with the conventional methods using metal salts There is an advantage.

Another aspect of the present invention relates to a polyketone porous film produced by the above-described method for producing a porous film of polyketone.

The polyketone porous membrane according to the present invention has an advantage that it can be applied to the field of microfiltration.

The polyketone porous membrane according to the present invention is manufactured by using a heat-induced phase separation method instead of a conventional method using a metal salt, and has a higher polyketone content than the conventional method and thus has an excellent mechanical strength and a high elongation.

In another embodiment of the present invention, the polyketone porous membrane may have a pure water permeability of 10 to 420 LMH / bar, specifically 30 to 420 LMH / bar, more specifically 100 to 420 LMH / bar. The polyketone porous membrane according to the present invention is excellent in pure water permeability and can be applied as a microfiltration membrane in a separation process containing an organic solvent.

In another embodiment of the present invention, the polyketone porous membrane may have a breaking strength of 1 to 7.78 MPa, specifically 2 to 7.78 MPa, more particularly 5 to 7.78 MPa. The polyketone porous membrane according to the present invention can be applied to a separation membrane field which is excellent in breaking strength and needs high strength.

In another embodiment of the present invention, the polyketone porous film may have an elongation of 10 to 278%, specifically 50 to 278%, more specifically 150 to 278%. The polyketone porous membrane according to the present invention can be applied to a separation membrane field which requires a high elongation and a high elongation.

Another aspect of the present invention relates to a polyketone flat membrane separator comprising the aforementioned polyketone porous membrane.

In still another embodiment of the present invention, the polyketone flat membrane type separator may be an organic solvent nanofiltration, an organic solvent resistant nanofiltration, an organic solvent resistant membrane, Or a gas separation membrane.

The polyketone flat membrane type separator according to the present invention can be manufactured by a heat-induced phase separation method instead of the conventional polyketone separation membrane process, which is complicated and uses a water-soluble metal salt aqueous solution and can not be produced by the non- It is advantageous that the mechanical strength is not deteriorated and excellent chemical resistance and heat resistance are obtained.

The polyketone flat membrane type separator according to the present invention is applied to various fields such as essential oils, medicines, and catalyst fields that require separation in an organic solvent as well as water and water treatment fields due to excellent chemical resistance and thermal resistance characteristics of polyketone Efficient, and cost-effective.

Hereinafter, the present invention will be described in detail by way of examples to illustrate the present invention. However, the embodiments according to the present disclosure can be modified in various other forms, and the scope of the present specification is not construed as being limited to the above-described embodiments. Embodiments of the present disclosure are provided to more fully describe the present disclosure to those of ordinary skill in the art. In the following, "% " and " part " representing the content are by weight unless otherwise specified.

Example  One

150 g of polyketone (Hyosung, POK, M630A) and 150 g of glycerol triacetate were placed in a high-temperature mixer, nitrogen with no reactivity was poured into the flask, nitrogen was replaced with nitrogen, and the mixture was stirred at 220 ° C for 4 hours in a propeller- To prepare a uniform dope solution. After stirring for 4 hours, low-speed stirring at 10 rpm was maintained for 1 hour to remove bubbles generated during stirring.

A support made of polyethylene terephthalate was mounted between the blade for manufacturing the porous membrane and the glass plate, and the gap between the blade and the glass plate was adjusted to 250 탆. The temperature of the blade and the glass plate was maintained at 220 캜. The dope solution from which the bubbles had been removed was charged into a flat film preparation apparatus so that the solidified thickness became 45 μm, and was applied on the support at a speed of 6 m / min.

The prepared porous membrane was immersed in an aqueous refrigerant composed of 10 wt% of glycerol triacetate and 90 wt% of water to induce solidification of the polyketone flat membrane. The temperature was adjusted to 25 ° C. The solidified polyketone flat membrane was put into a washing tank containing pure water and the diluent existing in the membrane was extracted for 3 hours. The pure porous membrane was examined for pure permeation, fracture strength and elongation, and the results are shown in Table 1. An electron scanning microscope was used to observe the three-dimensional structure of the dried porous membrane. The cross-section and the surface of the polyketone porous membrane thus produced are shown in Figs.

Example  2

A polyketone porous membrane was prepared in the same manner as in Example 1 except that 60 g of polyketone (Hyosung, POK, M630A) and 140 g of glycerol triacetate were used. The cross-section and the surface of the polyketone porous membrane thus produced are shown in Figs.

Comparative Example  One

60 g of polyvinylidene fluoride (Solvay, Solef 6020) and 140 g of glycerol triacetate were placed in a high-temperature mixer, and nitrogen, which had not been reacted, was poured therein to replace the air inside with nitrogen. And stirred with a propeller-shaped stirrer to prepare a uniform dope solution. After stirring for 3 hours, low-speed stirring at 10 rpm was maintained for 1 hour to remove bubbles generated during stirring.

A support made of polyethylene terephthalate was mounted between the knife for manufacturing the porous membrane and the glass plate, and the gap between the knife and the glass plate was adjusted to 250 탆. The temperature of the knife and the glass plate was maintained at 190 캜. The dope solution from which the air bubbles had been removed was charged into a flat film production apparatus and applied on a support at a speed of 6 m / min. Pure water was used to solidify the polyvinylidene fluoride porous membrane. The temperature was adjusted to 25 ° C. The solidified polyvinylidene fluoride porous membrane was placed in a washing tank containing pure water, and a diluent existing in the membrane was extracted for 3 hours. Except for this, in the same manner as in Example 1, the final separation membrane was subjected to pure water permeation test, breaking strength and elongation, and an electron scanning microscope was used to observe the three-dimensional structure of the dried membrane. The cross-section and the surface of the polyvinylidene fluoride porous membrane thus produced are shown in FIGS. 5 and 6. FIG.

The net water permeability, fracture strength, elongation and weight reduction rate of Examples 1 and 2 and Comparative Example 1 were evaluated in the following manner, and the results are shown in Tables 1, 2, 7, and 8.

Pure water permeability

Examples and Comparative Examples by a porous membrane effective film membrane module of area 75 cm ² produced according to the production inlet pressure 1 kgf / cm ^2, electron amount to be injected, and permeability to pure water into the membrane module to a water temperature 25 ℃ And the weight was confirmed by the balance, and the amount of pure water was measured using the following formula (1).

[Formula 1]

(LMH, Liter / m ² · h · bar) = [Liter] / [effective membrane area (m ² ) Х unit time (h)

Breaking strength and Elongation

 The fracture strength and elongation of the porous membrane prepared according to Examples and Comparative Examples were measured at a tensile rate of 50 mm / min using an universal material testing machine (AGS-J). The measurement was carried out in a room at 25 ° C.

Chemical resistance

The porous membranes of Examples 1 and 2 and Comparative Example 1 were cut into 3 cm × 3 cm and stored in dimethylformamide having 100 weight% and methylpyrrolidone solvent for 7 days, respectively, and the weight loss was evaluated.

division Pure water permeability (L / m ² h, at 1 bar) Breaking Strength (MPa) Elongation (%) Example 1 420 7.10 278 Example 2 315 7.78 250 Comparative Example 1 69 4.30 140

The pure water permeability of the polyketone porous membrane prepared in Example 1 as shown in Tables 1, 7 and 8 was 420 L / m ² h (at 1 bar), the breaking strength was 7.10 MPa, and the elongation was 278%. The pure water permeability of the polyketone porous membrane prepared in Example 2 was 315 L / m ² h (at 1 bar), the breaking strength was 7.780 MPa, and the elongation was 250%. It is considered that the weight of the diluent is increased because the weight% of the polyketone of Example 1 is lower than that of Example 2, which contributes to formation of large pores in the porous membrane.

The pure water permeability of the polyvinylidene fluoride porous membrane prepared in Comparative Example 1 was 69 L / m ² h (at 1 bar), the breaking strength was 4.30 MPa, and the elongation was 140%. It is considered that the reason why the breaking strength is weak even though the weight percentage of the polymer is the same as the weight of Example 2 and the manufacturing method is the same is as shown in FIG. 5 because the structure of the structure based on the solid-liquid phase separation is predominant.

division Weight reduction rate (%, DMF for 7 days) Weight reduction rate (%, NMP for 7 days) Example 1 1.2 1.5 Example 2 0.9 1.4 Comparative Example 1 100 (melts within 2 minutes) 100 (melts within 2 minutes)

Table 2 above shows the results of an experiment to confirm the chemical resistance of a separation membrane in a strong organic solvent such as dimethylformamide or methylpyrrolidone. The porous membrane prepared in Example 1 was supported on dimethylformamide and methylpyrrolidone having a weight of 100 wt% for 7 days, respectively, and weight loss was observed. As a result, the weight loss was 1.2 and 1.5 wt%, respectively. The weight loss rate of the porous membrane prepared in Example 2 was 0.9 and 1.4%, respectively. The polyketone flat membrane was found to be very stable in strong organic solvents such as dimethylformamide or methylpyrrolidone.

On the other hand, even in the case of polyvinylidene fluoride having relatively good chemical resistance in the polymer membrane material, as shown in Comparative Example 1, it was impossible to conduct the experiment because it was dissolved in the solvent within 2 minutes after the chemical resistance test.

Claims (20)

Heating a mixture of a polyketone and a diluent to a temperature above the melting point of the polyketone to melt the polyketone to prepare a dope solution;
Applying the dope solution on a support, solidifying the aqueous solution using an aqueous coolant containing at least one selected from the group consisting of water and an organic solvent to produce a polyketone porous membrane; And
Removing the diluent from the porous membrane;
≪ / RTI > The method according to claim 1,
With respect to 100 wt% of the entire dope solution,
10 to 50% by weight of the polyketone; And
50 to 90% by weight of the diluent;
≪ / RTI > wherein the polyketone porous film is formed from a polyketone porous film. The method according to claim 1,
Wherein the organic solvent is contained in an amount of 5 to 50 wt% based on 100 wt% of the aqueous refrigerant. The method according to claim 1,
Wherein the temperature at which the mixture of the polyketone and the diluent is heated is a temperature equal to or lower than a melting point of the polyketone and a boiling point or lower of the aqueous refrigerant. 5. The method of claim 4,
Wherein the temperature for heating the mixture of the polyketone and the diluent is 190 to 270 ° C. The method according to claim 1,
And stirring the dope solution to remove bubbles in the dope solution. The method according to claim 6,
Wherein the step of stirring the dope solution is carried out at a speed of 10 to 800 rpm for 1 to 12 hours. The method according to claim 1,
Wherein the temperature of the aqueous coolant is in the range of 4 to 70 占 폚. The method according to claim 1,
Wherein the support comprises thermoplastic synthetic fibers. 10. The method of claim 9,
Wherein the support is a nonwoven fabric or a nanofiber web having a basis weight of 60 to 100 g / m < ² >. The method according to claim 1,
The diluent may be selected from the group consisting of dimethyl phthalate, dibutyl phthalate, dioctyl phthalate, gamma -butyrolactone, diethyl phthalate, propylene glycol, At least one selected from the group consisting of ethylene glycol, glycerol triacetate, diphenyl ketone, dibutyl sebacate and liquid paraffin. By weight based on the total weight of the polyketone porous film. The method according to claim 1,
The organic solvent may be at least one selected from the group consisting of dibutyl phthalate, dioctyl phthalate, gamma -butyrolactone, diethyl phthalate, propylene glycol, ethylene glycol Wherein the polyketone porous film comprises at least one selected from the group consisting of ethylene glycol, glycerol triacetate, polyethylene glycol and glycerol. The method according to claim 1,
Wherein the solidified thickness after the application of the dope solution onto the support is from 10 to 50 mu m. The method according to claim 1,
Wherein the speed at which the dope solution is applied is 1 m / min to 30 m / min. A polyketone porous membrane produced by the process for producing a porous film of polyketones according to any one of claims 1 to 14 and having a pure water permeability of 300 to 420 LMH / bar. delete 16. The method of claim 15,
Wherein the polyketone porous membrane has a breaking strength of 1 to 7.78 MPa. 16. The method of claim 15,
Wherein the polyketone porous membrane has an elongation of 10 to 278%. 15. A polyketone flat membrane separator comprising the polyketone porous membrane according to claim 15. 20. The method of claim 19,
The polyketone flat membrane type membrane may be an organic solvent nanofiltration membrane, an organic solvent resistant nanofiltration membrane, an organic solvent resistant membrane membrane, or a gas separation membrane membrane membrane. A polyketone flat membrane.

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