JP5876696B2 - Polyketone porous membrane - Google Patents

Description

  The present invention relates to a polyketone porous membrane and its use.

  In recent years, in the semiconductor manufacturing process, the biopharmaceutical manufacturing process, etc., from the viewpoint of product reliability and yield, a filter medium that can efficiently remove impurities such as very fine particles and viruses has been demanded. If a filter medium having a pore size smaller than the size of the symmetrical filter is used, the impurities can be removed to some extent. However, generally, the smaller the pore size, the greater the pressure loss in filtration and the lower the permeation flux. Therefore, there is a demand for a filter medium that can sufficiently filter very small impurities and has little pressure loss. In addition, since various chemicals and organic solvents are used in the above process, the filter medium needs chemical resistance. Some filters may be corrosive when the process gas / liquid is an organic solvent and may be used in a high temperature environment. In such cases, the filter is often required to have chemical resistance, chemical stability, heat resistance, and the like. Currently, polyethylene porous membranes or polytetrafluoroethylene porous membranes are used as filter media that can remove minute impurities and have chemical resistance. However, the polyethylene porous membrane has a problem of low heat resistance. Further, the polytetrafluoroethylene porous membrane is very expensive, and there is a problem that it is difficult to make a filter medium having a pore diameter capable of removing minute impurities of about 10 nm. Furthermore, both of the above filter media are hydrophobic, and when filtering an aqueous treatment liquid, the filter media must be subjected to hydrophilic treatment in advance, or the filter media must be used after being immersed in alcohol before use. There's a problem.

  On the other hand, a porous film is also used as a separator as a constituent member for preventing contact between an anode and a cathode in a lithium ion secondary battery, an electric double layer capacitor, an electrolytic capacitor, or the like. In recent years, demands for heat resistance and insulation have increased for the separator from the viewpoint of safety and product life. As a separator of a lithium ion secondary battery currently used, a porous film made of polyethylene or polypropylene is mainly used. However, since polyethylene and polypropylene have poor heat resistance, there is a risk that a separator using these resins melts and softens at a high temperature and shrinks, and the anode and cathode come into contact with each other to cause a short circuit. Cellulose-based paper is mainly used in electric double layer capacitors and electrolytic capacitors, but 1-ethyl-3-methylimidazolium tetra is used in solvents such as γ-butyrolactone, which have been developed for high temperature resistance. Cellulose is decomposed or dissolved at a high temperature by an electrolytic solution in which an ionic liquid such as fluoroboric acid is dissolved as an electrolyte, so that there is a problem that the life of the product is short.

  By the way, an aliphatic polyketone (hereinafter also referred to as a polyketone) obtained by polymerizing carbon monoxide and an olefin by using palladium or nickel as a catalyst and completely and alternately copolymerizing carbon monoxide and the olefin is known. Due to its high crystallinity, polyketone has properties such as high mechanical properties, high melting point, organic solvent resistance and chemical resistance when it is made into a fiber or film. In particular, when the olefin is ethylene, the melting point of the polyketone is 240 ° C. or higher. Such a polyketone is excellent in heat resistance as compared with, for example, polyethylene. Therefore, the polyketone porous film obtained by processing polyketone to form a porous film also has heat resistance and chemical resistance. Furthermore, since polyketone has an affinity with water and various organic solvents, and since carbon monoxide and ethylene as raw materials are relatively inexpensive, the polymer price of polyketone may be reduced. The porous membrane is expected to be industrially utilized as a filter medium. Furthermore, when the polyketone porous film is in the form of a flat film, it can be used as a separator that can solve the above-described problems of lithium ion secondary batteries and various capacitors.

  The fact that the polyketone porous membrane is useful as a filter medium is described in, for example, Patent Document 1 and Patent Document 2. The polyketone porous film described in Patent Document 1 is manufactured by wet film formation using hexafluoroisopropanol as a solvent and water or isopropanol as a non-solvent. Moreover, the polyketone porous film described in Patent Document 2 is produced by wet film formation using a concentrated metal salt aqueous solution as a solvent.

Japanese Patent Laid-Open No. 2-4431 JP 2002-348401 A

  However, the porous membrane obtained by the method of Patent Document 1 has a very dense layer formed in the vicinity of the surface, and the pore diameter of this layer is very small, so that the pressure loss when used as a filter medium is extremely large. In addition, this very dense layer causes an increase in the internal resistance of the battery or capacitor in the application of the battery or capacitor separator.

  Further, the polyketone porous film obtained by the method of Patent Document 2 has a structure in which particulate crystals are grown or a structure having droplet-like pores, and the pore diameter is partially or entirely large. With this structure, it is impossible to remove minute impurities and the like with high efficiency in a filter application or a battery or capacitor application. In addition, there is a problem that insulation is low in battery or capacitor applications. Furthermore, in Patent Document 2, since a zinc salt or a calcium salt is used as a solvent, it is difficult to completely eliminate residual metal after film formation, washing, and drying from the polyketone porous film. Therefore, the polyketone porous film described in Patent Document 2 is not suitable as a filter medium in the field where metal impurities are hated, and as a separator for batteries or capacitors.

  The problems to be solved by the present invention include heat resistance and chemical resistance, and, for example, as a filter for filtration with high collection efficiency of minute impurities, low permeation resistance of ions and the like, and insulating properties. It is an object to provide a polyketone porous membrane useful as a separator for a battery having a high value or a capacitor.

  As a result of intensive studies to solve the above problems, the present inventors have found that a polyketone porous film having a maximum pore diameter, a ratio of a dense layer thickness to a non-dense layer thickness, and a porosity within a predetermined range is the above-mentioned problem. The present invention has been found to solve the problem. Specifically, the present invention has the following aspects.

[1] A polyketone porous membrane containing 10 to 100% by mass of a polyketone, which is a copolymer of carbon monoxide and one or more olefins, under the following conditions (1) to (3):
(1) The maximum pore size of the polyketone porous membrane is 1 μm or less;
(2) The porosity of the polyketone porous membrane is 5 to 90%; and (3) the polyketone porous membrane has a polyketone portion formed only by the polyketone over the film thickness direction. And a dense layer having a polymer filling ratio of 80% or more and a non-dense layer having a polymer filling ratio of less than 80%, and a ratio T1: T2 between the thickness T1 of the dense layer and the thickness T2 of the non-dense layer is 1. : 99 to 50:50;
Satisfying the polyketone porous membrane.
[2] The polyketone is represented by the following general formula (1):
{In the formula, R represents a substituted or unsubstituted hydrocarbon group having 2 to 20 carbon atoms. } The polyketone porous membrane according to the above [1], comprising a repeating unit represented by
[3] The following formula (2) for the repeating unit constituting the polyketone:
The polyketone porous membrane according to the above [1] or [2], wherein the proportion of the 1-oxotrimethylene repeating unit represented by the formula is 70 mol% or more.
[4] In the general formula (1), R is hydrogen, halogen, hydroxyl group, ether group, primary amino group, secondary amino group, tertiary amino group, quaternary ammonium group, sulfonic acid group, sulfonic acid ester. Including one or more functional groups selected from the group consisting of groups, carboxylic acid groups, carboxylic acid ester groups, phosphoric acid groups, phosphoric acid ester groups, thiol groups, sulfide groups, alkoxysilyl groups, and silanol groups, The polyketone porous membrane according to [2] or [3].
[5] The repeating unit represented by the general formula (1) with respect to the repeating unit constituting the polyketone, wherein R is a hydroxyl group, an ether group, a primary amino group, a secondary amino group, a tertiary amino group, 4 Selected from the group consisting of quaternary ammonium groups, sulfonic acid groups, sulfonic acid ester groups, carboxylic acid groups, carboxylic acid ester groups, phosphoric acid groups, phosphoric ester groups, thiol groups, sulfide groups, alkoxysilyl groups, and silanol groups The polyketone porous membrane according to any one of the above [2] to [4], wherein the ratio of the repeating unit containing one or more functional groups is in the range of 0.1 to 30 mol%.
[6] The polyketone is represented by the following general formula (3):
{In the formula, R ¹ , R ² , and R ³ are each independently hydrogen, halogen, an alkyl group having 1 to 20 carbon atoms, a hydroxyl group, an ether group, a primary amino group, a secondary amino group, or a tertiary amino group. Group consisting of a group, a quaternary ammonium group, a sulfonic acid group, a sulfonic acid ester group, a carboxylic acid group, a carboxylic acid ester group, a phosphoric acid group, a phosphoric acid ester group, a thiol group, a sulfide group, an alkoxysilyl group, and a silanol group It is a substituent containing one or more functional groups selected from. } The polyketone porous membrane according to any one of the above [1] to [5], which is a copolymer containing a structure represented by
[7] The polyketone porous membrane according to the above [6], wherein in the general formula (3), R ¹ and R ² are both hydrogen.
[8] The polyketone porous membrane according to any one of the above [1] to [7], further comprising at least one nonwoven fabric combined with the polyketone.
[9] The nonwoven fabric is composed of thermoplastic synthetic fibers, and the nonwoven fabric layer (A) having a fiber diameter of 5 to 20 μm and the nonwoven fabric layer (B) having a fiber diameter of 0.5 to 4 μm are A / B. The polyketone porous membrane according to the above [8], which is composite-integrated with / A type or A / B type.
[10] The polyketone porous membrane according to any one of the above [1] to [9], which is in the form of a flat membrane.
[11] The polyketone porous membrane according to any one of the above [1] to [9], which is a hollow fiber membrane having one or more voids penetrating in the longitudinal direction.
[12] A filter for filtration comprising the polyketone porous membrane according to any one of [1] to [11].
[13] The above-mentioned [12], which is a water treatment filter, a membrane bioreactor filter, an industrial liquid filtration filter, a degassing filter, a gas dust filter, a chemical filter, a gas separation filter, or a medical filter. ] The filter for filtration as described in above.
[14] A separator for a lithium ion secondary battery including the polyketone porous film according to [10].
[15] A capacitor separator including the polyketone porous film according to [10].
[16] The capacitor separator according to [15], wherein the capacitor is an electrolytic capacitor, an electric double layer capacitor, or a lithium ion capacitor.
[17] A developing phase for immunochromatography, comprising the polyketone porous membrane according to [10].
[18] A scaffold for cell culture, comprising the polyketone porous membrane according to [10].

  The polyketone porous membrane of the present invention is formed using a polyketone having excellent heat resistance and chemical resistance, and has a controlled porous structure. Therefore, when the polyketone porous membrane of the present invention is used as a filter for filtration, the collection efficiency of minute impurities is high, and a wide variety of fluids can be filtered in a wide temperature range. Furthermore, the filtration filter using the polyketone porous membrane of the present invention has low fluid resistance and sufficiently captures impurities to be removed, so that low energy and efficient filtration is realized. Moreover, the lithium ion secondary battery and various capacitors in which the polyketone porous film of the present invention is used as a separator have low internal resistance, high heat resistance, high insulation, and long life. Furthermore, the polyketone porous membrane of the present invention can also be used as an immunochromatographic development phase with little variation in the liquid absorption rate and as a scaffold for cell culture capable of culturing normal spherical cells.

It is an image which shows the expanded cross section of the polyketone porous film in 1 aspect of this invention. It is an image which shows the expanded cross section of the polyketone porous film in 1 aspect of this invention. It is a schematic diagram of the hollow fiber membrane as a polyketone porous membrane in one mode of the present invention. It is a cross-sectional schematic diagram of the polyketone porous film formed by combining polyketone and non-woven fabric in one embodiment of the present invention. It is a cross-sectional schematic diagram of the polyketone porous film formed by combining polyketone and non-woven fabric in one embodiment of the present invention. It is a cross-sectional schematic diagram of the polyketone porous film formed by combining polyketone and non-woven fabric in one embodiment of the present invention. It is an image which shows the expanded cross section of the dense layer in the polyketone part of the polyketone porous film in 1 aspect of this invention. It is a schematic diagram of the spinneret used in order to form the hollow fiber membrane as a polyketone porous membrane in one mode of the present invention.

  The present invention is a polyketone porous membrane containing 10 to 100% by mass of a polyketone which is a copolymer of carbon monoxide and one or more olefins, and the following conditions (1) to (3): (1) polyketone porous The maximum pore diameter of the membrane is 1 μm or less; (2) the porosity of the polyketone porous membrane is 5 to 90%; and (3) the polyketone porous membrane is formed only of polyketone across the film thickness direction. The polyketone part has a dense layer having a polymer filling ratio of 80% or more and a non-dense layer having a polymer filling ratio of less than 80%. The thickness T1 of the dense layer and the non-dense layer A polyketone porous membrane satisfying that the ratio T1: T2 to the thickness T2 is 1:99 to 50:50.

  The present invention also provides various members using the polyketone porous membrane of the present invention. In one aspect, a filter for filtration comprising a polyketone porous membrane according to the present invention is provided. Examples of filtration filters include water treatment filters, membrane bioreactor filters, industrial liquid filtration filters, degassing filters, gas dust filters, chemical filter filters, gas separation filters, and medical filters. Can be mentioned. In another aspect, a separator for a lithium ion secondary battery including the polyketone porous membrane according to the present invention is provided. In another aspect, a capacitor separator comprising a flat membrane-like polyketone porous membrane is provided. Examples of the capacitor include an electrolytic capacitor, an electric double layer capacitor, and a lithium ion capacitor. In another aspect, a development phase for immunochromatography and a scaffold for cell culture comprising a flat polyketone porous membrane are provided.

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

One aspect of the present invention is a polyketone porous membrane containing 10 to 100% by mass of a polyketone, which is a copolymer of carbon monoxide and one or more olefins, under the following conditions (1) to (3):
(1) The maximum pore size of the polyketone porous membrane is 1 μm or less;
(2) The porosity of the polyketone porous membrane is 5 to 90%; and (3) the polyketone porous membrane has a polyketone portion formed only by the polyketone over the film thickness direction. And a dense layer having a polymer filling ratio of 80% or more and a non-dense layer having a polymer filling ratio of less than 80%, and a ratio T1: T2 between the thickness T1 of the dense layer and the thickness T2 of the non-dense layer is 1. : 99 to 50:50;
A polyketone porous membrane that satisfies the above requirements is provided. The polyketone porous membrane according to one embodiment of the present invention may be substantially composed of only a polyketone, or may be composed of a composite of a polyketone and another material (for example, one or more nonwoven fabrics).

  The polyketone porous membrane contains 10 to 100% by mass of polyketone which is a copolymer of carbon monoxide and one or more olefins. The content of the polyketone in the polyketone porous film is preferably as large as possible from the viewpoint of reflecting the heat resistance and chemical resistance inherent in the polyketone. In the case of a flat film that is not combined with another material, the polyketone content in the polyketone porous film is preferably 70 to 100% by mass, more preferably 80 to 100% by mass, and still more preferably 90 to 100% by mass. In addition, in the polyketone porous composite film in which a nonwoven fabric or the like is combined, the polyketone content in the polyketone porous composite film from the viewpoint of achieving both the heat resistance and chemical resistance of the polyketone and the mechanical properties of the nonwoven fabric etc. 10-70 mass% is preferable, 10-60 mass% is more preferable, 10-50 mass% is still more preferable. The polyketone content in the polyketone porous membrane is determined by a method of dissolving and removing the polyketone with a solvent that dissolves only the polyketone among the components constituting the porous membrane, or a method of dissolving and removing other than the polyketone with a solvent that dissolves other than the polyketone Confirmed by.

  In the synthesis of the polyketone, as the olefin to be copolymerized with carbon monoxide, any type of compound can be selected depending on the purpose. Examples of the olefin include chain olefins such as ethylene, propylene, butene, hexene, octene, and decene, alkenyl aromatic compounds such as styrene and α-methylstyrene, cyclopentene, norbornene, 5-methylnorbornene, tetracyclododecene, Examples thereof include cyclic olefins such as tricyclodecene, pentacyclopentadecene and pentacyclohexadecene, halogenated alkenes such as vinyl chloride and vinyl fluoride, acrylic acid esters such as ethyl acrylate and methyl methacrylate, and vinyl acetate. From the viewpoint of the mechanical properties and heat resistance of the polyketone porous membrane, the number of types of olefins to be copolymerized is preferably 1 to 3, more preferably 1 to 2, and even more preferably 1 type. preferable.

  In one preferred form of the invention, the polyketone is represented by the following general formula (1):

{In the formula, R represents a substituted or unsubstituted hydrocarbon group having 2 to 20 carbon atoms. } Is included. R is hydrogen, halogen, hydroxyl group, ether group, primary amino group, secondary amino group, tertiary amino group, quaternary ammonium group, sulfonic acid group, sulfonic acid ester group, carboxylic acid group, carbon One or more functional groups selected from the group consisting of acid ester groups, phosphate groups, phosphate ester groups, thiol groups, sulfide groups, alkoxysilyl groups, and silanol groups can be included. The repeating unit constituting the polyketone (that is, the ketone repeating unit) can be one type or a combination of two or more types.

  From the viewpoint of the mechanical properties and heat resistance of the polyketone porous membrane, the carbon number of R in the general formula (1) is more preferably 2-8, still more preferably 2-3, and most preferably 2. In particular, the repeating unit constituting the polyketone has the following formula (2):

It is more preferable that it contains more 1-oxotrimethylene repeating units represented by From the viewpoint of mechanical properties and heat resistance, the proportion of 1-oxotrimethylene repeating units in the repeating units constituting the polyketone is preferably 70 mol% or more, more preferably 90 mol% or more, More preferably, it is 95 mol% or more. The proportion of 1-oxotrimethylene repeating units may be 100 mol%. On the other hand, the repeating unit constituting the polyketone may contain 0.1 mol% or more of a structure other than the 1-oxotrimethylene repeating unit as described later. In addition, the said 100 mol% means here that repeating units other than 1-oxo trimethylene are not observed except for a polymer terminal group in analyzers, such as a well-known elemental analysis, NMR (nuclear magnetic resonance), and gas chromatography. Say. Typically, the structure of the repeating unit constituting the polyketone and the amount of each structure are confirmed by NMR.

  The polyketone porous membrane has a maximum pore size of 1 μm or less. The maximum pore diameter is a value measured by a bubble point method (according to ASTM F316-86 or JIS K3832). When a polyketone porous membrane having a maximum pore size of 1 μm or less is used as, for example, a filter medium, the collection efficiency of fine particles on the order of submicrometers, which have high removal needs in semiconductor manufacturing processes, biopharmaceutical manufacturing processes, and the like is high. In addition, for example, in a battery or a capacitor in which the polyketone porous film is used as a separator, the insulating property is very high, and the electrodes do not easily come into contact with each other, and a short circuit can be prevented. The maximum pore size of the polyketone porous membrane is more preferably 0.5 μm or less, further preferably 0.3 μm or less, and most preferably 0.2 μm or less. On the other hand, the maximum pore size of the polyketone porous membrane is preferably 0 from the viewpoint that, for example, it is possible to favorably avoid a decrease in pressure loss and permeation flow rate in filter media applications, or to avoid an increase in internal resistance in separator applications. 0.001 μm or more, more preferably 0.005 μm or more, and still more preferably 0.01 μm or more.

  The polyketone porous film has a polyketone portion which is a portion formed only by the gap formed by the polyketone and the polyketone across the film thickness direction. The polyketone portion has a dense layer having a polymer filling ratio of 80% or more and a non-dense layer having a polymer filling ratio of less than 80%. The ratio of the dense layer thickness T1 to the non-dense layer thickness T2 is 1:99 to 50:50. In the dense layer, the polyketone occupies a significantly larger volume than the void portion in the cross-sectional visual field in the film thickness direction of the polyketone portion. The dense layer typically extends continuously in the plane direction of the porous film. The non-dense layer is a layer composed of a portion other than the dense layer. The dense layer and the non-dense layer may be clearly distinguished by a microscope image or the like. On the other hand, for example, when the porosity of the polyketone portion continuously changes in the thickness direction of the porous film, the dense layer and the non-dense layer do not have to show a clear boundary.

  The polymer filling ratio is a value calculated by the following method from a cross-sectional image of the polyketone portion in the film thickness direction. First, the cross-sectional image is binarized and divided into a portion corresponding to the polyketone portion (bright portion) and a portion corresponding to the gap (dark portion). Next, a measurement section divided into 50 equal parts in the film thickness direction is set. The area of the bright part and the dark part is obtained for each of the 50 sections. The area ratio of the bright part to the whole is defined as the polymer filling ratio. A section where the polymer filling ratio is 80% or more is determined as a dense layer, and a section where the polymer filling ratio is less than 80% is determined as a non-dense layer. The above measurement is similarly performed on cross-sectional images of five fields of view. The ratio of the arithmetic average of the five fields determined for the dense layer and the arithmetic average of the five fields determined for the non-dense layer to the ratio of the thickness of the dense layer to the thickness of the non-dense layer To do. The detailed method for determining the ratio can be based on the method described later in the [Example] section.

  FIG. 1 is an image showing an enlarged cross section of a polyketone porous membrane in one embodiment of the present invention. FIG. 1 is a cross-sectional image of a polyketone porous film composed only of polyketone by an electron microscope. In the cross section of the polyketone porous membrane shown in FIG. 1, it is shown that the ratio of the thicknesses of the dense layer 11 and the non-dense layer 12 defined by the above definition is within the predetermined range of the present invention. The polyketone porous membrane surface 3 has a large number of voids.

  FIG. 2 is an image showing an enlarged cross section of the polyketone porous film in one embodiment of the present invention. FIG. 2 is an electron microscope cross-sectional image of a polyketone porous film in which a polyketone and a polyester nonwoven fabric are combined. In the cross section of the polyketone porous film shown in FIG. 2, a polyketone portion 21 having a large number of micropores and a polyester fiber portion 22 constituting a nonwoven fabric appear. In the polyketone portion 23 composed only of the polyketone over the film thickness direction, the ratio of the thickness of the dense layer and the non-dense layer is within the predetermined range of the present invention as in the image shown in FIG.

  In filter applications, the dense layer is the most important layer in filtration because it contributes greatly to the fractionation performance. Therefore, the thicker the dense layer, the higher the fractionation ability, but at the same time, the pressure loss increases or the permeation flow rate decreases. On the other hand, in a battery or capacitor application, the thicker the dense layer, the better the insulation, but at the same time, the internal resistance increases. Further, when the film is composed only of the dense layer, the tensile, compressive, and bending stress acting on the film must be received only by the dense layer, and the film is easily damaged or the shape of the hole is easily changed. Thus, the presence of a non-dense layer is also important. Furthermore, in filter applications, when the non-dense layer is the primary side of filtration, the non-dense layer may serve as a pre-filter to remove coarse particles and prevent clogging, and to protect the dense layer. . Therefore, in the polyketone porous membrane of the present invention, it is important that the ratio of the thicknesses of the dense layer and the non-dense layer in the polyketone portion is controlled within a predetermined range.

  A polyketone porous film having a ratio of the dense layer to the non-dense layer having a ratio of the dense layer lower than 1:99 has extremely poor trapping efficiency of minute impurities in filter applications. In addition, in a battery or a capacitor in which the polyketone porous film is used as a separator, the insulating property is low and it is very easy to short-circuit. On the other hand, a polyketone porous membrane in which the ratio of the dense layer thickness to the non-dense layer thickness is higher than 50:50 has a very high pressure loss and a significantly low permeation flux in filter applications. In addition, in the battery or capacitor in which the polyketone porous membrane is used as a separator, the internal resistance is remarkably increased. The ratio of the thickness of the dense layer to the thickness of the non-dense layer is more preferably 2:98 to 45:55, and further preferably 5:95 to 40:60.

The polyketone porous membrane according to one embodiment of the present invention has a porosity of 5 to 90%. The porosity is the following formula:
Porosity (%) = (1−G / ρ / V) × 100
{In the formula, G is the mass (g) of the polyketone porous membrane, ρ is the mass average density (g / cm ³ ) of all resins constituting the polyketone porous membrane, and V is the volume (cm ³ ). }. In the above formula, the mass average density ρ is a value obtained by multiplying the density of each resin by its constituent mass ratio when the polyketone porous film is composed of a resin having a density different from that of the polyketone and a polyketone resin. Is the sum of For example, the [rho _A and [rho nonwoven density fibers with each are composed of a mass ratio of G _A and G _B of _B, and when the polyketone of the density [rho _p is combined in a mass ratio of G _p is weight average density Is the following formula:
Weight Mean Density _{= (ρ A · G A +} ρ B · G B + ρ p · G p) / (G A + G B + G p)
It is represented by When the polyketone porous membrane having a porosity of less than 5% is used as a filter medium, for example, the permeation flux is small, the particle collection efficiency is poor, and the time to block is short. In addition, for example, a battery or a capacitor in which the polyketone porous membrane is used as a separator is not preferable because the electrolyte retainability is low and the ion permeation rate is low. On the other hand, when the porosity of the polyketone porous film is higher than 90%, the polyketone porous film has extremely low mechanical strength, and frequently causes damage during production or use of filters, batteries, capacitors and the like. The porosity of the polyketone porous membrane of the present invention is preferably 30 to 90%, more preferably 40 to 90%, and most preferably 50 to 90%.

  In the present invention, the repeating unit constituting the polyketone is represented by the general formula (1) at a ratio of 30 mol% or less from the viewpoint of imparting the additional function as described later to the polyketone porous membrane. A repeating unit in which R is a hydroxyl group, an ether group, a primary amino group, a secondary amino group, a tertiary amino group, a quaternary ammonium group, a sulfonic acid group, a sulfonic acid ester group, a carboxylic acid group, a carboxylic acid ester group, Including a repeating unit (hereinafter also referred to as a substituent-containing unit) containing one or more functional groups selected from the group consisting of a phosphate group, a phosphate ester group, a thiol group, a sulfide group, an alkoxysilyl group, and a silanol group It is preferable. In a particularly preferred embodiment, the substituent-containing unit has a structure in which at least one hydrogen atom in the repeating unit represented by the formula (2) is substituted with one or more functional groups listed above.

  In the repeating unit constituting the polyketone, the ratio of the substituent-containing unit is preferably 0.1 to 30 mol%. When the proportion is 0.1 mol% or more, a practical effect due to the substituent is expressed well, and when it is 30 mol% or less, the strength (for example, tensile strength), heat resistance and chemical resistance of the polyketone porous film It is favorable in practical use. The above ratio is more preferably 0.2 to 15 mol%, still more preferably 0.5 to 10 mol%, in that the effect of the substituent is satisfactorily exhibited while maintaining strength, heat resistance and chemical resistance. 5 mol% is most preferred. The functional group can be selected in any kind and in any number depending on the purpose. For example, when a polyketone porous membrane is used as a filter medium, it is effective to select a hydrophilic functional group in order to avoid clogging due to adsorption of proteins and the like. Further, when the polyketone porous membrane is used as a battery or capacitor separator, the permeation resistance of ions or the like can be lowered by selecting a functional group that increases wettability with an electrolytic solution or the like. Depending on the purpose, a functional group having a secondary function may be selected. For example, by selecting a functional group such as a quaternary ammonium group and a sulfonic acid group, the polyketone porous membrane has ion exchange ability. Is also possible.

  From the viewpoint of imparting a good function to the polyketone porous membrane, the polyketone is represented by the following general formula (3):

{In the formula, R ¹ , R ² , and R ³ are each independently hydrogen, halogen, an alkyl group having 1 to 20 carbon atoms, a hydroxyl group, an ether group, a primary amino group, a secondary amino group, or a tertiary amino group. Group consisting of a group, a quaternary ammonium group, a sulfonic acid group, a sulfonic acid ester group, a carboxylic acid group, a carboxylic acid ester group, a phosphoric acid group, a phosphoric acid ester group, a thiol group, a sulfide group, an alkoxysilyl group, and a silanol group It is a substituent containing one or more functional groups selected from. } (Hereinafter also referred to as a pyrrole component). The mass ratio of the pyrrole component in the polyketone is preferably 30% by mass or less, and more preferably 0.1 to 30% by mass. When the mass ratio is 0.1% by mass or more, in a polyketone porous film containing a polyketone composed of a polyketone chain and the above components, a practical effect due to the inclusion of a pyrrole component is favorably expressed, and 30% by mass In the case of the following, the strength, heat resistance and chemical resistance of the polyketone porous membrane are good, which is convenient in practical use. The mass ratio is more preferably 0.5 to 20% by mass, and further preferably 1 to 10% by mass.

The substituents R ¹ , R ² , and R ³ in the general formula (3) can be selected from any kind and any number from the above substituents depending on the purpose. For example, when a polyketone porous membrane is used as a filter medium, it is effective to select a hydrophilic functional group in order to avoid clogging due to adsorption of proteins and the like. Further, when the polyketone porous membrane is used as a battery or capacitor separator, the permeation resistance of ions or the like can be lowered by selecting a functional group that increases wettability with an electrolytic solution or the like. Depending on the purpose, a functional group having a secondary function may be selected. For example, by selecting a functional group such as a quaternary ammonium group and a sulfonic acid group, it is possible to provide ion exchange ability. is there. Various functional groups can be selected like these. Among these, when R ¹ and R ² in the formula are both hydrogen, it is advantageous and preferable in terms of mechanical properties.

  The shape of the pores of the polyketone porous membrane is not particularly limited as long as it satisfies the above-mentioned maximum pore diameter, porosity, and the ratio of the thickness of the dense layer to the thickness of the non-dense layer, and may be round, flat, etc. it can. A porous membrane with mainly circular holes is preferable because it stabilizes the collection performance when used as a filter medium and the permeation performance of ions when used as a separator, for example, and can be easily applied to general fields. Has the advantage of being able to.

  The shape of the polyketone porous membrane is not particularly limited. However, as a preferred example, the polyketone porous membrane has a flat membrane shape, and as another preferred example, the polyketone porous membrane is a hollow fiber membrane having one or more voids penetrating in the longitudinal direction. The shape of the polyketone porous membrane can be properly used according to the purpose and application.

FIG. 3 is a schematic view of a hollow fiber membrane as a polyketone porous membrane in one embodiment of the present invention. The hollow fiber membrane 31 shown in FIG. 3 has at least one void 33 (hereinafter also referred to as a hollow portion) penetrating in the longitudinal direction. In the hollow fiber membrane 31 shown in FIG. 3, the hollow fiber membrane cross section 32 has a ring shape. Hollow fiber membranes are particularly suitable for filter applications. When the polyketone porous membrane is a hollow fiber membrane, the ratio of the hollow portion to the entire volume of the hollow fiber membrane including the volume of the hollow portion, that is, the hollow ratio is not particularly limited, but if it is too low, the separation efficiency of the membrane tends to decrease. If it is too high, the mechanical properties of the hollow fiber membrane tend to deteriorate. From such a viewpoint, the hollow ratio is preferably 10 to 70% by volume, and more preferably 20 to 60% by volume. The hollow ratio is calculated from the following calculation formula from the inner diameter r and outer diameter R of the hollow fiber membrane:
Hollow ratio (%) = (r ² / R ² ) × 100
Is calculated according to

  There is no restriction | limiting in particular in the number of the hollow parts which one hollow fiber membrane has, One piece or multiple pieces may be sufficient. Although there is no restriction | limiting in particular in the outer diameter of a hollow fiber membrane, The range of 100-5000 micrometers is used suitably. The hollow fiber membrane may be used alone or as a multifilament. As the cross section of the hollow fiber membrane, a conventionally known shape such as a circle, an ellipse, a triangle, a star, and an alphabet can be applied. The thickness of the hollow fiber membrane (for example, the thickness T in the hollow fiber membrane shown in FIG. 2) is selected depending on the balance between the outer diameter and the hollowness, but is usually 8 to 1700 μm.

  In another example, the polyketone porous membrane is a sheet-like flat membrane. A flat membrane is suitable not only as a filter medium but also when used as a separator for a battery or a capacitor. The thickness of the flat membrane is not particularly limited and can be any thickness depending on the application, but is usually 0.1 to 1000 μm. When the polyketone porous membrane is used as a filter medium, the thickness of the polyketone porous membrane is preferably small, and is preferably 500 μm or less, from the viewpoint of downsizing the module and wide effective filtration area. The thickness of the polyketone porous membrane as the filter medium is more preferably 200 μm or less, further preferably 150 μm or less, and most preferably 100 μm or less. Further, when the polyketone porous membrane is used as a separator for a battery or a capacitor, the thickness of the polyketone porous membrane is preferably small, preferably 70 μm or less, in consideration of improvement in battery capacity, miniaturization of the capacitor, and the like. The thickness of the polyketone porous film as a battery or capacitor separator is more preferably 50 μm or less, further preferably 40 μm or less, and most preferably 30 μm or less. In consideration of mechanical strength in both of the above applications, the thickness of the polyketone porous membrane is preferably 5 μm or more, more preferably 10 μm or more, further preferably 15 μm or more, and preferably 20 μm or more. Most preferred. Further, in both of the above applications, the uniformity of the thickness of the polyketone porous film is very important, and the ratio of the minimum value / maximum value of the thickness measured at 100 arbitrary points is 0.6 or more. Preferably, it is 0.7 or more, more preferably 0.8 or more.

  In one aspect, the polyketone porous membrane of the present invention may further include at least one nonwoven fabric combined with the polyketone. FIGS. 4-6 is a cross-sectional schematic diagram of the polyketone porous film | membrane with which the polyketone and the nonwoven fabric in 1 aspect of this invention were compounded. With reference to FIGS. 4-6, the example of the form with which the polyketone and the nonwoven fabric were compounded is shown below. For example, as shown in FIG. 4, a form in which a flat film-like polyketone portion 41 and a nonwoven fabric portion 42 are bonded with their surfaces as interfaces. Moreover, as shown in FIG. 5, the form which has the composite part 53 which the polyketone penetrate | infiltrated into the polyketone part 51, the nonwoven fabric part 52, and the nonwoven fabric is mentioned. Furthermore, as shown in FIG. 6, there is a form having a polyketone portion 61 and a composite portion 63 formed by completely enclosing a non-woven fabric (in which the polyketone is permeated). Can be mentioned. For example, an embodiment having a composite part as shown in FIGS. 5 and 6 is preferable in that the phenomenon in which the polyketone and the nonwoven fabric are peeled off is suppressed. Further, in the flat membrane-like polyketone porous film, the polyketone portion may be combined on one side of the nonwoven fabric portion or may be combined on both surfaces of the nonwoven fabric portion.

  As said nonwoven fabric, a generally well-known thing can be used according to the objective and a use. There is no limitation in particular in the fiber which comprises a nonwoven fabric, A short fiber and a spinning direct connection type | mold long fiber can be illustrated. In view of the possibility that the fibers constituting the nonwoven fabric will not fall off during use and the production cost, a spinning-coupled long fiber nonwoven fabric is preferred. Examples of the nonwoven fabric used in the present invention include polyester resins, polyamide resins, polyolefin resins, polyphenylene sulfide resins, and fluorine resins. Examples of the polyester resin include polyethylene terephthalate, polytrimethylene terephthalate, and polybutylene terephthalate. Examples of polyamide resins include nylon 6, nylon 66, nylon 610, nylon 612, and the like. Examples of the polyolefin resin include polyethylene and polypropylene. Examples of the polyphenylene sulfide-based resin include oxidation-crosslinked and linear resins. Examples of the fluorine-based resin include polytetrafluoroethylene and polyvinylidene fluoride.

  In general, a polyester resin is used when importance is attached to heat resistance, and a polyolefin resin is used when importance is attached to chemical resistance. When it is desired to achieve both heat resistance and chemical resistance, polyphenylene sulfide resin or fluorine resin is used. In view of good processability, polyphenylene sulfide-based resins are preferable. All the nonwoven fabrics may be hydrophilized by plasma irradiation or the like as necessary.

  The nonwoven fabric is preferably made of thermoplastic synthetic fibers. The nonwoven fabric has a structure in which a nonwoven fabric layer (A) having a fiber diameter of 5 to 20 μm and a nonwoven fabric layer (B) having a fiber diameter of 0.5 to 4 μm (that is, ultrafine fibers) are A / B / A. It is preferable that it is formed of a mold or an A / B mold and integrated by bonding or the like. Nonwoven fabric is composed of fibers and voids that are the gaps between them, but by making the nonwoven fabric structure as described above, it does not create large voids that are continuously connected in the thickness direction, so it is combined with polyketone resin. Can be realized with a more uniform thickness. When the polyketone porous film has a structure in which a polyketone resin porous film is combined on one side of a nonwoven fabric, the fibers of the nonwoven fabric layer (B) having the ultrafine fibers are thin and the voids are small. There is an effect of suppressing permeation to the opposite side of the coated surface, and a more uniform polyketone porous film can be produced. In addition, when a nonwoven fabric is A / B type, the polyketone may be compounded from the A surface side, or may be compounded from the B surface side. The fiber diameter is measured by observing a cross section of the polyketone porous film with an optical microscope or an electron microscope.

The intrinsic viscosity (this is an index of molecular weight) of the polyketone constituting the polyketone porous membrane of the present invention is not particularly limited, but is 0.1 to 10 dl / g from the viewpoint of mechanical properties and moldability. preferable. A polyketone porous membrane composed of a polyketone having an intrinsic viscosity of 0.1 dl / g or more has high strength and is suitable for use as a filter medium. Furthermore, the polyketone having an intrinsic viscosity of 0.1 dl / g or more has a low content of oligomer components that are readily soluble in water and various organic solvents. A polyketone porous membrane obtained by molding such a polyketone is suitably used as a filter medium that does not allow impurities to be mixed, or as a separator for batteries or capacitors. On the other hand, a polyketone having an intrinsic viscosity of 10 dl / g or less is advantageous in terms of production cost, and is advantageous in practical use because it can be easily formed into a porous film having a uniform thickness. The intrinsic viscosity of the polyketone is more preferably 0.5 to 6 dl / g. The intrinsic viscosity is defined as follows:
{In the formula, t and T are the flow times of a viscosity tube at 25 ° C. of a diluted solution of hexafluoroisopropanol having a purity of 98% or more and a polyketone dissolved in hexafluoroisopropanol, respectively. C is a solute (ie, polyketone) mass value in grams in 100 ml of the solution. } Is a value obtained based on.

  The melting point of the polyketone contained in the porous membrane of the present invention is not particularly limited, but the higher the melting point of the polyketone, the more advantageous for use in a high temperature environment. The melting point of the polyketone is preferably 180 ° C. or higher, more preferably 200 ° C. or higher, still more preferably 220 ° C. or higher, and most preferably 240 ° C. or higher. The melting point is the endothermic starting point due to melting of the polyketone in the temperature rising process of differential heat measurement.

  The tensile strength of the polyketone porous membrane is preferably 2 MPa or more, more preferably 2.5 MPa or more, from the viewpoint of good handleability in producing a filter, battery or capacitor, and high productivity. More preferably, it is 3 MPa or more. The tensile strength is a value measured as a breaking strength using a tensile strength tester.

  In the polyketone porous membrane of the present invention, the number and position of the dense layers are not particularly limited as long as the ratio of the thickness of the dense layer to the thickness of the non-dense layer is maintained within the predetermined range of the present invention. For example, in the case of a flat film, the dense layer may be on only one surface, on both surfaces, or inside the membrane. Also in the case of a hollow fiber membrane, the dense layer may be on either the outer peripheral side or the inner peripheral side, may be on both sides, or may be inside the membrane. When there are a plurality of dense layers, the ratio of the sum of the thicknesses of the dense layers to the sum of the thicknesses of the non-dense layers may be in the above range.

  FIG. 7 is an image showing an enlarged cross section of the dense layer in the polyketone portion of the polyketone porous film in one embodiment of the present invention. The dense layer shown in FIG. 7 is composed of fibrous polyketone. In the polyketone porous membrane of the present invention, the dense layer of the polyketone portion can have a fibrous structure as shown in FIG. Thereby, a hole can be formed in the dense layer.

  In the case where the dense layer is a fibrous polyketone structure, the ratio of the number of those having a thickness of 0.5 μm or less to the total number of fibrous materials constituting the dense layer is preferably 60% or more. When the ratio is 60% or more, a so-called slip flow effect is satisfactorily produced in use as a filter medium, and the fluid permeation resistance is reduced. In addition, when used as a separator for batteries and capacitors, the permeation resistance of ions and the like is reduced because there are few thick fibrous structures. The ratio is more preferably 70% or more, and still more preferably 80% or more. The said ratio is calculated by the method of binarizing the image which image | photographed the cross section of the polyketone porous film with the scanning electron microscope in the procedure mentioned later, and performing image processing.

In the polyketone porous film, the pore portion does not contribute to the strength, so stress and strain are concentrated on the polyketone serving as the support. For this reason, it is preferable that the microstructure of the polyketone is a strong structure. In particular, the crystallinity is an important parameter, and the higher the value, the higher the strength, the higher dimensional stability, the higher heat resistance, and the higher the chemical resistance. Therefore, the crystallinity of the polyketone is preferably 35% or more, more preferably 40% or more, and further preferably 50% or more. The degree of crystallinity (%) is the degree of crystallinity when the endothermic peak area of melting during differential heating measurement is ΔH (J / g) and the heat of fusion of the polyketone crystal is ΔH ₀ (J / g). %) = ΔH / ΔH ₀ × 100.

When the polyketone porous membrane of the present invention is used as a non-aqueous filter medium or a separator for batteries or capacitors, it is preferable that the moisture absorption rate is low. Here, the moisture absorption rate is T ₀ when the polyketone porous membrane is completely dried in an oven at 105 ° C. for 2 hours, and then T ₁ after being left at 23 ° C. and RH 50% for 24 hours. Then, the moisture absorption rate = (T ₁ −T ₀ ) / T ₀ × 100 (%). When the moisture absorption rate of the polyketone porous membrane is high, when used as a filter medium, the moisture itself becomes an impurity, or the moisture may cause hydrolysis of the object to be filtered, thereby generating further impurities. In addition, when the polyketone porous membrane is used as a battery or capacitor separator, gas is generated by electrolysis of water, the generated gas causes expansion of the battery or capacitor, deteriorates the electrode, and the battery or capacitor. May cause performance degradation. Therefore, the moisture absorption rate of the polyketone porous membrane is preferably 3% or less, more preferably 1% or less, and still more preferably 0.5% or less.

  The polyketone porous membrane of the present invention contains a functional substance such as an inorganic filler, a light stabilizer, an antioxidant, an antistatic agent, a hydrophilic polymer, and a protein-adsorbing substance within a range that does not hinder the original performance. But you can. Specifically, the polyketone porous film may contain glass fibers, inorganic fibers such as carbon fibers, or carbon nanotubes as inorganic fillers in order to increase mechanical strength, impact resistance, and heat resistance. In addition, the polyketone porous film may contain an ultraviolet absorber, a hindered amine light stabilizer, etc. as a light stabilizer in order to improve stability against light and oxidation, and a phenol, phosphorus, or sulfur as an antioxidant. A system antioxidant or the like may also be included. Further, the polyketone porous film may contain various surfactants as an antistatic agent. Moreover, in order to raise hydrophilicity, hydrophilic polymers, such as polyethyleneglycol, polyvinyl alcohol, polyvinylpyrrolidone, collagen, etc. may be included. Moreover, in order to raise protein adsorptivity, you may contain nitrocellulose etc.

  The total content of the functional substances is preferably 30 parts by mass or less with respect to 100 parts by mass of the polyketone porous membrane. When the total content is 30 parts by mass or less, it is preferable that the strength of the polyketone porous film is not lowered and the functional substance is not easily dropped and eluted. The total content is more preferably 20 parts by mass or less, and still more preferably 10 parts by mass or less.

  In the polyketone porous film, the polyketone may be three-dimensionally cross-linked for the purpose of improving chemical resistance and heat resistance, if necessary. Since the polyketone is three-dimensionally cross-linked, it is insolubilized in a solvent, and deformation against heat is improved. There are no particular limitations on the three-dimensional crosslinked structure, for example, an aldol condensation structure by heat treatment, a crosslinked structure by a diamine compound (that is, a pyrrole ring structure crosslinked by a methylene chain, see International Publication No. 2010/33027 for details), etc. Is mentioned. The three-dimensional crosslinking is preferably performed after forming the polyketone porous film. The preferred range of the degree of crosslinking reaction varies depending on the chemicals and solvent to be exposed and the temperature, but when the polyketone is stirred in hexafluoroisopropanol (25 ° C.) for 3 hours, the solids content does not dissolve but dissolves relative to the mass before dissolution. The ratio of the remaining mass is preferably 50% by mass or more, and more preferably 70% by mass or more.

  Next, an example of the manufacturing method of the polyketone porous membrane of this invention is demonstrated.

  There is no restriction | limiting in particular as a manufacturing method of the polyketone used as the raw material of a porous film, For example, it can manufacture using a well-known method as described in the international publication 2003/055934 pamphlet.

  The polyketone porous membrane is preferably produced by wet molding. That is, it is preferable to produce a polyketone dope by dissolving the polyketone obtained by the above-mentioned known method in a solvent, mold it into a desired shape, and then solidify, wash, and dry.

  Solvent for dissolving polyketone is not particularly limited, organic solvents such as hexafluoroisopropanol, propylene carbonate, m-cresol, aqueous solution of resorcin, zinc chloride, zinc chloride / calcium chloride, zinc chloride / lithium chloride, zinc chloride / calcium thiocyanate A known solvent such as an aqueous solution of a metal salt such as zinc chloride / calcium chloride / lithium chloride or zinc chloride / calcium chloride / calcium thiocyanate can be used. However, in order to produce a porous membrane in which the ratio between the thickness of the dense layer and the thickness of the non-dense layer is within the predetermined range of the present invention, the selection of the solvent and the combination of coagulation liquid for phase separation of the polyketone dope are performed. It becomes important. Specifically, it is important to select a solvent that sufficiently dissolves the polyketone as the solvent and a non-solvent that causes phase separation of the polyketone dope at an appropriate rate as the coagulating liquid. For the above reasons, hexafluoroisopropanol, m-cresol, an aqueous solution of resorcin, and the like are preferable as the solvent used for producing the polyketone porous membrane. Hereinafter, a method using an aqueous solution of resorcin will be described as an example of the method for producing the polyketone porous membrane of the present invention.

  The resorcin concentration in the resorcin solution is preferably 60 to 80% by mass, more preferably 65 to 75% by mass from the viewpoint of solubility of the polyketone. The polyketone powder is mixed with the aqueous solution of resorcin, heated and stirred, and defoamed under reduced pressure or under pressure as necessary to form a polyketone dope. The combination of the intrinsic viscosity of the polyketone used and the polyketone concentration in the dope (hereinafter also referred to as the polymer concentration) is a mechanical strength that maintains the structure of the polyketone porous membrane, moldability, and a viewpoint of ensuring uniform dissolution. Therefore, a combination in which the intrinsic viscosity is 0.1 to 10 dl / g and the polymer concentration is in the range of 1 to 50% by mass is preferable, and the intrinsic viscosity is 0.5 to 6 dl / g and the polymer concentration is in the range of 3 to 20% by mass. The combination of is more preferable. The combination is appropriately determined in consideration of the viscosity of the polyketone dope and the structure of the polyketone porous film. Particularly, since the polymer concentration affects the pore size of the final polyketone porous membrane, the adjustment thereof is important.

  An example of a production method when the polyketone porous membrane is a sheet-like flat membrane is given. When the polyketone is molded into a sheet shape, a relatively low dope viscosity is suitable for moldability. From this viewpoint, the dope viscosity at the molding temperature is preferably 10 to 1000 poise. When the dope viscosity is 10 poise or more, the dope does not easily flow excessively, it is easy to keep the film shape uniform, and a flat film with few defects can be formed. On the other hand, when the dope viscosity is 1000 poise or less, it is preferable in that it is easy to make the thickness of the polyketone porous film uniform. The dope viscosity is more preferably 50 to 500 poise. The dope viscosity is measured with a B-type viscometer while being kept at the molding temperature.

  As a method for forming a flat membrane, a batch method includes a method in which a dope is cast into a sheet shape on an upper surface of a substrate such as a glass plate, a metal plate, or a plastic film using an applicator. In the continuous method, using a device such as a die coater, roll coater, bar coater, etc., a method of continuously applying a polyketone dope to a traveling substrate in a sheet form, a polyketone dope in a sheet form from a T-die or the like in the air A method of extruding to the surface can be used. Although the dope temperature at the time of application | coating or extrusion is adjusted suitably in order to make said preferable dope viscosity, normally 15-90 degreeC is preferable. When the temperature is 15 ° C. or higher, the increase in the dope viscosity can be suppressed and the thickness of the film can be made uniform easily, and the precipitation of resorcin in the dope can be avoided. When the temperature is 90 ° C. or lower, a change in the composition of the dope due to evaporation of water in the solvent can be avoided, and target structure control is easy.

  Next, the sheet-like polyketone dope applied or extruded into the air is immersed in a coagulating liquid in which resorcin can be dissolved, such as methanol, water, or a mixed solvent thereof. It is preferable that a predetermined amount of resorcin is contained in the coagulation liquid in terms of enabling stable management of the coagulation liquid composition in consideration of solvent recovery. The composition of the solvent in the coagulation liquid and the temperature of the coagulation liquid are important conditions for controlling the structure of the polyketone porous film, and are appropriately selected in consideration of the combination with the solvent composition. When the resorcinol aqueous solution is used as the polyketone dissolving solvent, it is preferable to use methanol or a solvent in which methanol and water are mixed at an appropriate ratio as the coagulating liquid. In the case of a mixed solvent of methanol and water, the mixing mass ratio is preferably methanol: water = 0: 100 to 30:70 in constructing the structure of the polyketone porous membrane of the present invention. When the mass ratio of methanol to water in the coagulation liquid is 30:70 or less than this, the thickness of the dense layer and the non-dense layer of the resulting polyketone porous film can be controlled well. Moreover, it is preferable that the temperature of the said coagulation liquid is -20 degreeC-70 degreeC. When the temperature of the coagulation liquid is −20 ° C. or higher, precipitation of resorcin in the film in the coagulation step can be avoided, and formation of a final pinhole can be avoided. When the coagulating liquid temperature is 70 ° C. or lower, it is possible to avoid the entire film from becoming dense. The temperature of the coagulation liquid is more preferably 0 to 60 ° C.

  The flat film coagulated by the above-described method is further washed with a coagulating liquid or the like, and the coagulating liquid contained in the film is replaced with another solvent as necessary. The purpose of solvent replacement is to increase the efficiency of drying when drying the coagulated film, and to prevent the structure of the polyketone porous film from being deformed due to shrinkage during drying or the like. From the viewpoint of suppressing deformation of the polyketone porous membrane structure or increasing the porosity, a solvent having a surface tension lower than that of water is preferable as a solvent to be replaced from the coagulation bath. Specifically, methanol, ethanol, normal propyl alcohol, isopropyl Lower or higher alcohol solvents such as alcohol, normal butanol and normal octanol, ether solvents such as diethyl ether, tetrahydrofuran and 1,4-dioxane, ketone solvents such as acetone and methyl ethyl ketone, methylene chloride, chloroform and carbon tetrachloride And low-polar organic solvents such as normal pentane, normal hexane, cyclohexane, normal heptane, normal octane, benzene and toluene. Moreover, the solvent used for solvent substitution may contain additives, such as surfactant, as needed. Furthermore, low polar organic solvents such as normal pentane, normal hexane, cyclohexane, normal heptane, normal octane, benzene and toluene are particularly preferable in terms of obtaining a polyketone porous film having a high porosity.

  In the case where the solidified flat membrane contains water, the solvent replacement may be performed in advance with a solvent such as acetone that is easily mixed with both the water and the low polarity solvent in order to smoothly perform the solvent replacement with the low polarity solvent. As the solvent that replaces the coagulation liquid, a solvent having a low surface tension is preferable, and specifically, toluene, cyclohexane, normal hexane, and the like are preferable. If these solvents contain a highly polar solvent, the homogeneity of the structure of the polyketone porous film tends to be impaired. Therefore, it is important to increase the number of substitutions or to increase the purity of the solvent used for substitution as much as possible. The purity of the solvent used for substitution is preferably 90% by mass or more, more preferably 95% by mass or more, still more preferably 98% by mass or more, and most preferably close to 100% by mass. Moreover, when the coagulation membrane is washed with water, it is preferable to treat the polyketone coagulation membrane after water washing with hot water at 60 to 200 ° C. under normal pressure or pressure as necessary. This treatment has an effect of preventing the pore structure from being deformed due to shrinkage or the like when drying the solidified film. The above treatment is an important condition for controlling the structure of the polyketone porous membrane and adjusting it within a predetermined range, although the treatment method and the necessity thereof vary depending on the type of the solvent and the coagulation liquid. In particular, the replacement of normal hexane and the hot water treatment are preferable in terms of increasing the crystallinity of the polyketone porous film and providing mechanical strength and thermal stability.

  The flat membrane is dried by a known drying method such as a method of contacting a heating roll, a method of spraying hot air, a method of drying by non-contact heating with an electric heater, or a combination of these, and the like. A polyketone porous membrane is obtained. The drying temperature is appropriately selected in the range of 15 to 200 ° C. depending on the type of liquid to be dried. Moreover, you may provide the chemical | medical agent which prevents generation | occurrence | production of static electricity before drying or after drying before winding a polyketone porous film or stacking as needed.

  The flat membrane-like polyketone porous membrane obtained as described above may be stretched as necessary. Stretching may be performed in only a uniaxial direction or in a biaxial direction, but the total stretching ratio is preferably 5 times or less. When the draw ratio is 5 times or less, it is advantageous in avoiding breakage of the flat membrane-like polyketone porous membrane during stretching. Stretching may be performed immediately after the polyketone dope is coagulated in the coagulation liquid, or may be performed after drying the flat film-like polyketone porous film, if necessary, by heating. When carrying out heat stretching, it is preferable that the stretching speed is 0.5 cm or less per second per 1 cm length. In many cases, the fibrous structure constituting the pores of the polyketone porous membrane is very thin with a thickness of about 1 μm or less, and has a high porosity, so that the stretching speed is preferably slow. When the flat membrane-like polyketone porous membrane has a flat hole, it is stretched 1.2 to 5 times by uniaxial stretching or the total stretching ratio does not exceed 5 times in biaxial stretching. Within a range, it is preferable that the draw ratio of one axis is 1.2 times or more of the draw ratio of the other axis.

  Next, an example of the manufacturing method in case a polyketone porous membrane is a hollow fiber membrane is given. In the case of a hollow fiber membrane, a relatively high viscosity of the polyketone dope is suitable for forming a hollow shape. From this viewpoint, the dope viscosity at the molding temperature is preferably 100 to 5000 poise. When the dope viscosity is 100 poise or more, yarn breakage hardly occurs during molding of the polyketone hollow fiber membrane, and it becomes easy to continuously produce yarn. On the other hand, when the dope viscosity is 5000 poise or less, it is easy and preferable to form an internal hollow. The dope viscosity is more preferably 200 to 4000 poise, and further preferably 300 to 2000 poise. Although the dope temperature at the time of extrusion is adjusted suitably in order to make said preferable dope viscosity, 20-90 degreeC is preferable normally. When the temperature is 20 ° C. or higher, an excessive increase in the viscosity of the dope can be avoided to make the thickness of the film uniform, and precipitation of a solute in the dope can be avoided. When the temperature is 90 ° C. or lower, a change in the composition of the dope due to evaporation of the solvent in the dope can be avoided, and target structure control becomes easy.

  The polyketone hollow fiber membrane can be produced using a spinneret such as a double tube orifice or a C-type orifice. FIG. 8 is a schematic view of a spinneret used for forming a hollow fiber membrane as a polyketone porous membrane in one embodiment of the present invention, and shows an example of a cross-sectional structure of a cylindrical double tube orifice. When the double-tube orifice 83 is used, it is preferable that polyketone dope is discharged from the outer ring-shaped orifice 81 and liquid or gas is discharged from the inner circular orifice 82 into the air. The discharge from the inner circular orifice is preferably a gas from the viewpoint of controllability of the hollow fiber membrane shape, and is preferably a liquid from the viewpoint of spinning stability and control of the porous structure. When gas is discharged from the inner circular orifice, dried nitrogen is preferred as the gas. When liquid is discharged from the inner circular orifice, for example, when a dense layer is formed on the inner layer side of the polyketone hollow fiber membrane, a mixed liquid having a mass ratio of methanol: water = 0: 100 to 30:70 is used. Is preferred. Moreover, when not forming a dense layer in the inner layer side of a polyketone hollow fiber membrane, it is preferable to use the liquid mixture which is a mass ratio of methanol: water = 30: 70-0: 100. In this case, it is necessary to form a dense layer at the center in the thickness direction of the polyketone hollow fiber membrane or on the outer layer side. Therefore, for example, in the subsequent coagulation step, the coagulation liquid can be a mixed liquid having a mass ratio of methanol: water = 0: 100 to 30:70. Further, from the viewpoint of maintaining the shape of the hollow portion, the liquid or gas flowing from the inner circular orifice is preferably discharged under a pressure of 0.01 MPa or more.

  Next, a solidified microporous structure is formed by precipitating polyketone from the polyketone dope extruded into the air in a dry or wet manner. When a resorcin solution is used as a solvent, the polyketone dope extruded into the air and filled with a gas or liquid in the hollow part is immersed in a coagulating liquid in which resorcin can be dissolved, such as methanol, water, or a mixed solvent thereof. To do. As the coagulation liquid, the same coagulation liquid as in the case of a flat membrane is preferably used. Then, the solidified hollow fiber membrane is subjected to washing and solvent replacement or hot water treatment as necessary in the same manner as the flat membrane. The drying process may or may not be performed. If it is performed, the drying is performed under the same conditions as the flat film.

  The polyketone hollow fiber membrane obtained as described above may be stretched as necessary. Stretching is performed in a uniaxial direction, and the stretching ratio is preferably 5 times or less. When it is 5 times or less, the polyketone hollow fiber membrane is preferably not broken during stretching. The stretching may be performed immediately after the polyketone dope is coagulated in the coagulating liquid, or may be performed after drying the polyketone hollow fiber membrane, if necessary, by heating. When carrying out heat stretching, it is preferable that the stretching speed is 0.5 cm or less per second per 1 cm length. Since the fibrous structure defining the pores of the polyketone porous membrane is often a very thin structure with a thickness of about 1 μm or less and a high porosity, the stretching speed is preferably slow. When making the hole of a polyketone hollow fiber membrane into a flat hole, it is preferable to perform 1.2 to 5 times extending | stretching by uniaxial direction extending | stretching.

  The compounding method in the case of compounding the polyketone and the non-woven fabric is not particularly limited, but there are a batch type or a continuous type, a method in which the polyketone part and the non-woven fabric are pressure-bonded to each other and a method in which the polyketone and the non-woven fabric are fused by heating. Can be mentioned. Moreover, after apply | coating polyketone dope to the single side | surface or both surfaces of a nonwoven fabric, the method of drying after coagulation | solidification by the above-mentioned method, washing | cleaning, and solvent substitution or warm water treatment as needed is mentioned. Furthermore, after applying the polyketone dope on the substrate or the nonwoven fabric, and overlaying the nonwoven fabric on it with an appropriate pressure, after solidifying, washing, and solvent replacement or hot water treatment as necessary, by the above method, There is also a method of drying. These methods are preferred because the polyketone portion penetrates into the nonwoven fabric and the adhesive strength between the polyketone portion and the nonwoven fabric increases. When a polyketone dope is applied to one side of a nonwoven fabric, a relatively high dope viscosity is suitable for molding, and the dope viscosity at the molding temperature is preferably 100 to 5000 poise. When the dope viscosity is 100 poise or more, the dope does not penetrate too much into the nonwoven fabric, and the film thickness of the polyketone portion becomes uniform. On the other hand, when it is 5000 poise or less, since the dope can be satisfactorily penetrated into the nonwoven fabric, the nonwoven fabric and the polyketone are easily combined, the dope application state is uniform, and the thickness of the nonwoven fabric composite polyketone porous membrane is It becomes uniform. The dope viscosity is more preferably 200 to 2000 poise.

  In the case of substituting at least one hydrogen atom of the polyketone constituting the polyketone porous membrane with another group from the viewpoint of imparting a desired function to the polyketone porous membrane, examples of the substitution method include electron beam, γ-ray, plasma, etc. And a method of adding a reactive monomer having a functional group that expresses a desired function after generating a radical in the polyketone by irradiation. Examples of the reactive monomer include acrylic acid, methacrylic acid, vinyl sulfonic acid and derivatives thereof, allylamine, p-vinylbenzyltrimethylammonium chloride, and the like. The substitution treatment may be performed before the polyketone is molded into the porous film or may be performed after the polyketone is molded into the porous film, but is preferably performed after the polyketone is molded into the porous film from the viewpoint of moldability.

  Moreover, the following general formula (3):

{In the formula, R ¹ , R ² , and R ³ are each independently hydrogen, halogen, an alkyl group having 1 to 20 carbon atoms, a hydroxyl group, an ether group, a primary amino group, a secondary amino group, or a tertiary amino group. Group consisting of a group, a quaternary ammonium group, a sulfonic acid group, a sulfonic acid ester group, a carboxylic acid group, a carboxylic acid ester group, a phosphoric acid group, a phosphoric acid ester group, a thiol group, a sulfide group, an alkoxysilyl group, and a silanol group It is a substituent containing one or more functional groups selected from. }, Any method is possible. However, it is convenient to produce a polyketone containing the above structure by a dehydration condensation reaction between the polyketone and a primary amine. Is preferable. Primary amines include ethylamine, 1-propylamine, isopropylamine, 1-butylamine, isobutylamine, tert-butylamine, 1-hexylamine, 1-dodecylamine, monoethanolamine, terminal amino group-containing polyethylene glycol, ethylenediamine, Propanediamine, N-methylethylenediamine, N-methylpropanediamine, N, N-dimethylethylenediamine, N, N-dimethylpropanediamine, 4-aminopyridine, aminomethanesulfonic acid, aminoethanesulfonic acid, 3-aminobenzenesulfonic acid , Sodium 3-aminobenzenesulfonate, sulfanilic acid, sodium sulfanilate, glycine, glycine methyl ester, O-phosphoethanoldiamine, cysteine, cysteamine, Thionine, methionine methyl ester, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, and the like. The dehydration condensation reaction may be performed before the polyketone is formed into a porous film or may be performed after the polyketone is formed into a porous film. However, from the viewpoint of moldability, it is preferably performed after the polyketone is formed into a porous film.

  Next, although an Example and a comparative example demonstrate this invention concretely, this invention is not limited to these.

  The measuring method of each measured value in an Example and a comparative example is as follows.

(1) Intrinsic viscosity of polyketone The intrinsic viscosity [η] (unit: dl / g) of polyketone is defined by the following formula:

{In the formula, t and T are the flow times of a viscosity tube at 25 ° C. of a diluted solution of hexafluoroisopropanol having a purity of 98% or more and a polyketone dissolved in hexafluoroisopropanol, respectively. C is a solute (ie, polyketone) mass value in grams in 100 ml of the solution. } Is a value obtained based on.

(2) Maximum pore diameter Porous Materials, Inc. Using a perfluoropolyester (trade name “Galwick”, surface tension of 15.6 dyn / cm) manufactured by the company, the maximum pore size (μm) was measured by the bubble point method in accordance with ASTM F316-86 or JIS K3832.

(3) Ratio between dense layer thickness and non-dense layer thickness A polyketone porous membrane is enclosed in a gelatin capsule together with ethanol, cleaved in a state where the ethanol is frozen by immersion and cooling in liquid nitrogen, and the cross section in the thickness direction is cut. Prepared. Using a scanning electron microscope (JSM-6700F: manufactured by JEOL Ltd.), an image with a magnification of 500 to 5000 times was obtained from the obtained section. The photographed negative image was analyzed by the following method using an image analyzer (IP1000-PC: manufactured by Asahi Kasei Corporation). Using a scanner (JX-330: manufactured by Sharp Corporation), a negative image was captured with 256 black and white gradations (gamma correction value 2.2). The capture area was selected according to the shooting magnification. A binarization process was performed on the captured 256-gradation image. The parameters set at this time are (1) threshold value (= automatic), (2) shading correction processing (= present), (3) hole filling processing (= present), and (4) gamma correction processing (= correction value). γ = 2.2). Subsequently, the area ratio was measured from the obtained binarized image. Specifically, the portion formed by the polyketone and the voids (holes) defined by the polyketone across the film thickness direction is the measurement area, and 1/50 of the distance in the film thickness direction of the measurement area is the section pitch. . In each section, the area of the bright part (corresponding to the polyketone part) and the dark part (corresponding to the gap) was measured, and the area ratio of the bright part when the total area of the bright part and the dark part was 100% was calculated. A section where the area ratio of the bright part was 80% or more was defined as a dense layer, and a section lower than 80% was defined as a non-dense layer. Five fields of view were measured in the same procedure, and the ratio of the arithmetic average of the number of sections made into a dense layer and the arithmetic average of the number of sections made into a non-dense layer was the ratio of the dense layer thickness to the non-dense layer thickness. Calculated as

(4) Inner diameter and outer diameter of the hollow fiber membrane A cross section perpendicular to the longitudinal direction of the hollow fiber membrane was photographed with an optical microscope at any five locations, and the inner diameter and outer diameter at any two points were measured in each cross-sectional image. The average inner diameter r (μm) and the average outer diameter R (μm) of the hollow fiber membranes obtained as a total number of 10 points were taken as the inner diameter and outer diameter, respectively.

(5) In the case of film thickness / flat film Measurement using a dial gauge (Ozaki Mfg. Co., Ltd .: PEACOCK No. 25), selecting the film thickness of the polyketone porous film at 9 points (3 points x 3 points) at intervals of 5 mm in a grid pattern Measurement was made at a point, and the average thickness L _p (μm) obtained as the number average value was taken as the film thickness.
In the case of hollow fiber membrane From the average inner diameter r and average outer diameter R obtained in (4), the average thickness L _h (μm) of the hollow fiber membrane obtained according to (R−r) / 2 was defined as the film thickness.

(6) Porosity / flat membrane A test piece of 5 cm × 5 cm was cut out and its mass G (g) was measured. From the average thickness L _p (μm) determined in (5) and the mass average density ρ (g / cm ³ ), the following calculation formula:
Porosity (%) = {1-G / 5 ² / ρ / (L _p × 10 ⁻⁴ )} × 100
{The mass average density ρ in the formula is the mass average density calculated from the mass G, the mass density of polyketone, the mass density of polyester and polypropylene in the fibers constituting the nonwoven fabric, and the basis weight of the nonwoven fabric. } Was calculated. The mass densities of polyketone, polyester, and polypropylene were 1.3 g / cm ³ , 1.4 g / cm ³ , and 0.9 g / cm ³ , respectively.
In the case of hollow fiber membrane Ten test pieces having a yarn length of 5 cm were cut out and the total mass G (g) thereof was measured. From the average outer diameter R (μm) and average inner diameter r (μm) obtained in (4), the polyketone mass density is 1.3 g / cm ³ and the following calculation formula:
Porosity (%) = [1-G / 10 / 1.3 / 5 / {(R ² −r ² ) × 10 ⁻⁸ × π / 4}] × 100
Further, the porosity of the hollow fiber membrane was calculated.

(7) Hollow ratio Using the average inner diameter r and average outer diameter R determined in (4), the following calculation formula:
Hollow ratio (%) = (r ² / R ² ) × 100
Calculated from

(8) Ratio of fibrous structure having a thickness of 0.5 μm or less in the dense layer The section in the thickness direction obtained by the method of (3) was photographed at 10,000 times using a scanning electron microscope. From the obtained image, the thickness (namely, fiber diameter) and ratio of the fibrous structure in the dense layer of the polyketone portion were evaluated. After performing binarization processing in the same manner as in (3), further contraction separation processing is performed with 5 to 10 contractions, and the longitudinal direction of the tissue is the length in the main axis direction, and the direction perpendicular to the longitudinal direction is the main axis direction width. As for each value. Measurement points where the value obtained by dividing the length in the main axis direction by the width in the main axis direction was lower than 1.5 and the measurement points whose length in the main axis direction was less than 0.1 μm were judged as noise and were excluded. After the above measurement was performed in five arbitrary fields of view, the ratio of the number of measurement points with a width in the main axis direction of 0.5 μm or less to the total number of measurement points was calculated at 100 minutes. The obtained value was defined as the ratio (%) of the fibrous structure having a thickness of 0.5 μm or less to the fibrous structure in the dense layer of the polyketone part.

(9) Melting point and crystallinity of polyketone 5 mg of a polyketone porous film was sealed in an aluminum pan under a nitrogen atmosphere, and measured using a differential heat measuring device Pyris1 (trade name) manufactured by PerkinElmer under the following conditions.
Sample weight: 5mg
Atmosphere: Nitrogen, Nitrogen flow rate = 100 mL / min Temperature conditions: (i) Hold at 25 ° C. for 1 minute
(Ii) 25 ° C. → 300 ° C. (temperature increase rate = 10 ° C./min)
The rising temperature of the endothermic peak due to melting of the polyketone in the temperature raising process (ii) was defined as the melting point of the polyketone. Further, the crystallinity of the polyketone was determined from the endothermic peak size ΔH (J / g) by the following formula.
Polyketone crystallinity (%) = ΔH / ΔH ₀ × 100
{ΔH ₀ is the theoretical value (J / g) of the heat of fusion of the polyketone, and the value varies depending on the chemical structure of the polyketone. For example, in the case of a polyketone consisting only of 1-oxotrimethylene repeating units, ΔH ₀ = 225 J / g. }

(10) Tensile strength Using a horizontal tensile strength tester (manufactured by Kumagai Riki Kogyo Co., Ltd.), a sample cut into a strip shape with a width of 15 mm was broken at 5 points under the conditions of a distance between chucks: 80 mm and an extension speed: 80 m / min. The strength was measured, and the number average was taken as the tensile strength (MPa).

(11) Pressure loss per unit thickness / flat membrane A polyketone porous flat membrane is punched into a circle, and the flat membrane is fixed to a stainless steel holder (Advantech, effective filtration area 3.5 cm ² ), 1.4 mL / min The total amount of distilled water was filtered at / cm ² , the pressure loss at that time was measured, and the pressure loss per unit thickness (kPa / μm) was calculated by dividing by the thickness (μm).
・ In the case of hollow fiber membranes n hollow fiber membranes are bundled (n is 5 to 10), and both ends are embedded and cut with epoxy resin so that the effective filtration length is 5 cm. Evaluation was performed. One end of the mini-module is completely sealed, the whole amount of distilled water is filtered at 1.4 mL / min / cm ² , the pressure loss at that time is measured, and the pressure loss per unit thickness (μm) is divided ( kPa / μm) was calculated. Here, the effective filtration area (cm ² ) is calculated by the following formula using the average inner diameter r (μm) obtained in (3).
Effective filtration area (cm ² ) = n × 5 × π × r × 10 ⁻⁴

(12) Particle Collection Efficiency / Flat Membrane Using a flat polyketone porous membrane as a filter medium, a polystyrene latex aqueous dispersion having an average particle diameter of 50 nm and a particle concentration of 10 ppm is prepared with a differential pressure of 200 kPa and an effective filtration area of 3.5 cm ^2. The whole volume was filtered for 10 minutes. The particle concentration C (ppm) of the filtrate was measured, and the particle collection efficiency (%) was calculated from the following formula.
Particle collection efficiency (%) = (1−C / 10) × 100

・ In the case of hollow fiber membranes n hollow fiber membranes are bundled (n is 5 to 10), and both ends are embedded and cut with epoxy resin so that the effective filtration length is 5 cm. Evaluation was performed. One end of the mini-module was completely sealed, and a polystyrene latex aqueous dispersion having the same conditions as in the case of a flat membrane was filtered for 10 minutes at a differential pressure of 200 kPa. The particle concentration C (ppm) of the filtrate was measured, and the particle collection efficiency (%) was calculated from the above formula.

  The polystyrene concentration was measured by creating a calibration curve from a polystyrene latex aqueous dispersion having a known concentration using an ultraviolet-visible spectrophotometer (JASCO: V-650).

(14) Withstand voltage Measured in air at 23 ° C. in accordance with JIS C2110. The measurement result was divided by the average thickness of the sample measured in (4), and the value was described as 1 mm thickness conversion.

[Example 1]
A polyketone (polymer structure abbreviation: ECO) having an intrinsic viscosity of 3.4 dl / g in which ethylene and carbon monoxide are completely alternately copolymerized is added to a 65% by mass resorcinol aqueous solution at a polymer concentration of 10.7% by mass. By stirring and dissolving for 2 hours and defoaming, a uniform transparent dope was obtained.

  The dope at 50 ° C. was applied in a sheet form on a glass plate using an applicator so that the dope thickness was 100 μm. This sheet-like dope was immersed in water at 25 ° C. for 10 minutes to solidify, then washed with methanol and dried at 60 ° C. to obtain a flat membrane-like polyketone porous membrane.

  The obtained polyketone porous membrane had a maximum pore size of 0.06 μm, a porosity of 25%, and a ratio of the dense layer thickness to the non-dense layer thickness was 25:75. Further, the film thickness is 14 μm, the proportion of the fibrous structure having a thickness of 0.5 μm or less in the dense layer of the polyketone part is 82%, the melting point of the polyketone is 248 ° C., the crystallinity of the polyketone is 67%, and the tensile strength is 12. 5 MPa. The polyketone porous film was uniform with no large pores, such as pinholes, observed.

Using the polyketone porous membrane, the performance as a filtration membrane was evaluated. The pressure loss per unit thickness at the time of water filtration rate of 1.4 mL / min / cm ² was measured and found to be 49.2 kPa / μm. Further, when a polystyrene latex aqueous dispersion having an average particle size of 0.05 μm was filtered for 10 minutes, the particle collection efficiency was 99%. Thus, the polyketone porous membrane obtained in Example 1 was very excellent as a filter medium. The results are shown in Table 1.

[Example 2]
After coagulation and washing, a polyketone porous membrane was produced under the same conditions as in Example 1 except that the solvent was replaced in the order of acetone and normal hexane, and the drying temperature was 50 ° C. The performance of the polyketone porous membrane of this example is shown in Table 1.

[Example 3]
A polyketone porous membrane was prepared under the same conditions as in Example 2 except that a mixed liquid having a mass ratio of methanol / water of 25/75 was used instead of methanol as the coagulation liquid and the washing solvent. The performance of the polyketone porous membrane of this example is shown in Table 1.

[Example 4]
A polyketone porous film was produced under the same conditions as in Example 3 except that the dope thickness was 40 μm and the glass plate was coated in a sheet form. The performance of the polyketone porous membrane of this example is shown in Table 1.

[Example 5]
A polyketone porous film was produced under the same conditions as in Example 3 except that the dope thickness was 500 μm and the glass plate was coated in a sheet form. The performance of the polyketone porous membrane of this example is shown in Table 1.

[Example 6]
The same conditions as in Example 3 except that instead of a methanol / water mixture at a mass ratio of 25/75, a mixture of methanol / water / resorcinol at a mass ratio of 22.5 / 67.5 / 10 was used as the coagulation liquid. A polyketone porous membrane was prepared. The performance of the polyketone porous membrane of this example is shown in Table 1.

[Example 7]
A polyketone porous membrane was produced under the same conditions as in Example 3 except that the polymer concentration was 9.2% by mass. The performance of the polyketone porous membrane of this example is shown in Table 1.

[Example 8]
A polyketone porous membrane was produced under the same conditions as in Example 3 except that the polymer intrinsic viscosity was 4.9 dl / g and the polymer concentration was 9.2% by mass. The performance of the polyketone porous membrane of this example is shown in Table 1.

[Example 9]
The washing solvent is water, and the washed polyketone film is heated at 150 ° C. for 1 hour in an autoclave containing a sufficient amount of water so that the entire polyketone film is immersed, and then replaced with another solvent at 80 ° C. A polyketone porous film was produced under the same conditions as in Example 3 except that the film was dried at 1. The performance of the polyketone porous membrane of this example is shown in Table 1.

[Example 10]
Instead of a completely alternating copolymer of ethylene and carbon monoxide, a polyketone (polymer structure abbreviation: EPCO) of a terpolymer (extreme viscosity 2.0 dl / g) in which 6 mol% of ethylene is replaced with propylene is used. A polyketone porous membrane was produced under the same conditions as in Example 3 except that a dope was produced at a polymer concentration of 12% by mass. The performance of the polyketone porous membrane of this example is shown in Table 1.

[Example 11]
Instead of a completely alternating copolymer of ethylene and carbon monoxide, a polyketone (polymer structure abbreviation: EStCO) of a terpolymer (extreme viscosity 1.8 dl / g) in which 4 mol% of ethylene is replaced with styrene is used. A polyketone porous membrane was produced under the same conditions as in Example 3 except that a dope was produced at a polymer concentration of 12% by mass. The performance of the polyketone porous membrane of this example is shown in Table 1.

[Example 12]
Instead of a completely alternating copolymer of ethylene and carbon monoxide, a polyketone (polymer structure abbreviation: PCO) of a completely alternating copolymer of propylene and carbon monoxide (intrinsic viscosity 1.6 dl / g) is used. A polyketone porous membrane was produced under the same conditions as in Example 3 except that a dope was produced at a concentration of 12% by mass. The performance of the polyketone porous membrane of this example is shown in Table 1.

[Example 13]
Made of polyethylene terephthalate fibers having an average fiber through 16 [mu] m, unbonded filament web fiber layer having a basis weight of 10 g / m ² (nonwoven fabric layer A) is made of a microfine polyethylene terephthalate fibers having an average fiber diameter of 1.6μm basis weight 5 g / m ² A polyketone porous membrane was prepared by the following method using A / B / A type laminated nonwoven fabrics thermocompression bonded to the top and bottom of the random web ultrafine fiber layer (nonwoven fabric layer B).

  A polyketone dope at 50 ° C. produced under the same conditions as in Example 3 was applied to one side of the nonwoven fabric using an applicator so that the dope thickness was 35 μm. This polyketone dope / nonwoven fabric composite was coagulated, washed and dried under the same conditions as in Example 3 to obtain a polyester nonwoven fabric composite polyketone porous membrane. The polyketone mass ratio with respect to the total mass of the polyketone porous membrane was 11 mass%.

The polyketone porous membrane had a tensile strength of 32 MPa. Since the tensile strength of the polyketone porous membrane of Example 3 is 5.1 MPa, it can be said that the polyketone porous membrane of this Example is particularly excellent in tensile strength. The maximum pore diameter of the polyketone porous membrane of this example was 0.17 μm, the porosity was 49%, and the ratio of the dense layer thickness to the non-dense layer thickness was 17:83. Further, the film thickness was 48 μm, and the ratio of the fibrous structure having a thickness of 0.5 μm or less in the dense layer of the polyketone portion was 91%. Using the polyketone porous membrane of this example, the pressure loss per unit thickness at a water filtration rate of 1.4 mL / min / cm ² was measured and found to be 2.3 kPa / μm. Further, when a polystyrene latex aqueous dispersion having an average particle size of 0.05 μm was filtered for 10 minutes, the particle collection efficiency was 96%. The performance of the polyketone porous membrane of this example is shown in Table 1.

[Example 14]
Made of polypropylene fibers having an average fiber through 11 [mu] m, unbonded filament web fiber layer having a basis weight of 8 g / m ² is (nonwoven fabric layer A), an average basis weight 1 g / m ² composed of ultrafine polypropylene fibers having a fiber diameter of 1.6μm random web A polyketone porous membrane was prepared by the following method using A / B / A type laminated nonwoven fabrics thermocompression bonded to the top and bottom of the ultrafine fiber layer (nonwoven fabric layer B).

  A polyketone dope at 50 ° C. produced under the same conditions as in Example 3 was applied to one side of the nonwoven fabric using an applicator so that the dope thickness was 35 μm. This polyketone dope / nonwoven fabric composite was coagulated, washed and dried under the same conditions as in Example 3 to obtain a polypropylene nonwoven fabric composite polyketone porous membrane. The polyketone mass ratio in the total mass of the polyketone porous membrane was 19% by mass.

The polyketone porous membrane had a tensile strength of 22 MPa. The maximum pore diameter of the polyketone porous membrane of this example was 0.16 μm, the porosity was 52%, and the ratio of the dense layer thickness to the non-dense layer thickness was 16:84. Further, the film thickness was 41 μm, and the ratio of the fibrous structure having a thickness of 0.5 μm or less in the dense layer of the polyketone portion was 91%. Using the polyketone porous membrane of this example, the pressure loss per unit thickness at a water filtration rate of 1.4 mL / min / cm ² was measured and found to be 1.8 kPa / μm. Further, when a polystyrene latex aqueous dispersion having an average particle size of 0.05 μm was filtered for 10 minutes, the particle collection efficiency was 96%. The performance of the polyketone porous membrane of this example is shown in Table 1.

[Example 15]
An unbonded long fiber web fiber layer (nonwoven fabric layer A) having a basis weight of 3.3 g / m ² and composed of polyester filaments having an average fiber diameter of 16 μm is 1.4 g / m per unit area consisting of very fine polyester fibers having an average fiber diameter of 1.6 μm. A polyketone porous membrane was prepared by the following method using A / B / A type laminated nonwoven fabrics thermocompression bonded to the top and bottom of ² random web ultrafine fiber layers (nonwoven fabric layer B).

  A polyketone dope at 50 ° C. produced under the same conditions as in Example 3 was applied to one side of the nonwoven fabric using an applicator so that the dope thickness was 25 μm. This polyketone dope / nonwoven fabric composite was coagulated, washed and dried under the same conditions as in Example 3 to obtain a polyester nonwoven fabric composite polyketone porous membrane. The polyketone mass ratio in the total mass of the polyketone porous membrane was 33% by mass.

The polyketone porous membrane had a tensile strength of 21 MPa. The maximum pore diameter of the polyketone porous membrane of this example was 0.17 μm, the porosity was 62%, and the ratio of the dense layer thickness to the non-dense layer thickness was 17:83. The film thickness was 48 μm, and the proportion of the fibrous structure having a thickness of 0.5 μm or less in the dense layer of the polyketone portion was 90%. Using the polyketone porous membrane of this example, the pressure loss per unit thickness at a water filtration rate of 1.4 mL / min / cm ² was measured, and found to be 2.1 kPa / μm. Further, when a polystyrene latex aqueous dispersion having an average particle size of 0.05 μm was filtered for 10 minutes, the particle collection efficiency was 95%. The performance of the polyketone porous membrane of this example is shown in Table 1.

[Comparative Example 1]
A polyketone having an intrinsic viscosity of 3.9 dl / g in which ethylene and carbon monoxide are completely and alternatingly copolymerized into a 62% by mass metal salt aqueous solution with a polymer concentration of 8.5% by mass and zinc chloride / calcium chloride = 22/40% by mass. The mixture was added, dissolved by stirring at 80 ° C. for 2 hours and at 90 ° C. for 1 hour, and defoamed to obtain a uniform transparent dope.

  Using an applicator, this 90 ° C. dope was applied onto a glass plate so that the dope thickness was 500 μm. This was immersed in methanol at −20 ° C. for 10 minutes to solidify, and then immersed in water at 2 ° C. for 10 minutes. Subsequently, it was washed with 0.1% by mass hydrochloric acid and then with water. Subsequently, solvent substitution was performed in the order of acetone and tert-butanol. The obtained flat membrane was frozen with liquid nitrogen and then dried for 10 minutes under a reduced pressure of 0.01 Pa. Subsequently, boat drying was carried out at 160 ° C. for 20 seconds to obtain a flat polyketone porous membrane.

  The obtained polyketone porous membrane had a maximum pore size of 4.2 μm, a porosity of 45%, and a ratio of the dense layer thickness to the non-dense layer thickness was 10:90. The film thickness was 502 μm, the proportion of the fibrous structure having a thickness of 0.5 μm or less in the dense layer of the polyketone portion was 14%, and the tensile strength was 24 MPa. In the polyketone porous membrane, no large pores that were a defect such as pinholes were observed.

Using the polyketone porous membrane, the performance as a filtration membrane was evaluated. When the pressure loss per unit thickness when the water filtration rate was 1.4 mL / min / cm ² was measured, it was 0.10 kPa / μm, which was favorable. However, when a polystyrene latex aqueous dispersion having an average particle size of 0.05 μm was filtered for 10 minutes, the particle collection efficiency was 3%, which was not a satisfactory value. The results are shown in Table 1.

[Comparative Example 2]
Polyketone having an intrinsic viscosity of 3.4 dl / g obtained by completely alternating copolymerization of ethylene and carbon monoxide into a 62 mass% metal salt aqueous solution with a polymer concentration of 8.5 mass% and zinc chloride / calcium chloride = 22/40 mass ratio. The mixture was added, dissolved by stirring at 80 ° C. for 2 hours and at 90 ° C. for 1 hour, and defoamed to obtain a uniform transparent dope.

  Using an applicator, this 90 ° C. dope was applied on a glass plate so that the dope thickness was 100 μm. This was immersed in water at 25 ° C. for 10 minutes to solidify, then washed with 0.1% by mass hydrochloric acid, and then washed with water. The obtained flat film was dried at 105 ° C. for 60 minutes to obtain a flat polyketone porous film.

  The maximum pore size of the obtained polyketone porous membrane could not be measured with the measuring apparatus used this time, suggesting that it was lower than 0.015 μm. The porosity was 2%, and no non-dense layer was observed. The film thickness was 9 μm, the proportion of the fibrous structure having a thickness of 0.5 μm or less in the dense layer of the polyketone portion was 14%, and the tensile strength was 24 MPa. In the polyketone porous membrane, no large pores that were a defect such as pinholes were observed. The polyketone porous membrane did not allow water and polystyrene latex aqueous dispersion to permeate at 200 kPa, and pressure loss measurement and particle trapping efficiency measurement were impossible.

[Comparative Example 3]
A polyketone porous film was produced under the same conditions as in Example 3 except that a mixed liquid of 40/60 mass ratio of methanol / water was used as the coagulating liquid. The results are shown in Table 1.

[Comparative Example 4]
It is coated on a glass plate so that the dope thickness is 150 μm, and the washing solvent is water, and the washed polyketone porous film is in a bath containing a sufficient amount of water at 80 ° C. so that the polyketone porous film is completely immersed. A polyketone porous membrane was produced under the same conditions as in Example 3 except that the heat treatment was performed for 1 hour, and the film was dried at 80 ° C. without replacing with another solvent. The results are shown in Table 1.

[Example 16]
As shown in FIG. 8, the dope prepared in Example 3 was discharged from the circular orifice 81 outside the double tube kept at 25 ° C. using a cylindrical double tube orifice, and the circular orifice inside the double tube was discharged. From 82, the same mass mixture of methanol / water at 25 ° C. pressurized to 0.15 MPa was discharged. In the present embodiment, a double-tube orifice having a size of an outer diameter D1 = 0.8 mm, an outer diameter D2 = 0.4 mm, and an inner diameter D3 = 0.2 mm in FIG. 8 was used. The dope discharged from the orifice entered a coagulated liquid consisting of a mixed liquid having a mass ratio of 25/75 and a methanol / water ratio of 25/75 through an air gap of 10 mm while being pulled at a constant speed, and became coagulated yarn. The obtained polyketone coagulated yarn was washed with a mixed liquid having a mass ratio of methanol / water of 25/75, and then wound up into a skein. Subsequently, after skein was wound, it was replaced with acetone, further substituted with normal hexane, and then dried at 50 ° C. to obtain a hollow fiber membrane.

  The obtained hollow fiber membrane had a film thickness of 83 μm, an outer diameter of 469 μm, a hollowness of 42%, a maximum pore diameter of 0.16 μm, and a porosity of 69%. The dense layer is present in the outermost layer, the ratio of the dense layer thickness to the non-dense layer thickness is 10:90, the proportion of the fibrous structure having a thickness of 0.5 μm or less in the dense layer is 96%, and the tensile strength is 5.2 MPa. Met. The polyketone porous film was uniform with no large pores, such as pinholes, observed.

The performance as a filtration membrane was evaluated using the polyketone hollow fiber membrane. The pressure loss per unit thickness when the water filtration rate was 1.4 mL / min / cm ² was measured and found to be 8.7 kPa. Further, when a polystyrene latex aqueous dispersion having an average particle size of 0.05 μm was filtered for 10 minutes, the particle collection efficiency was 96%. Thus, the polyketone porous membrane obtained in Example 1 was very excellent as a filter medium. The results are shown in Table 2.

[Example 17]
As shown in FIG. 8, the dope prepared in Example 3 was discharged from the circular orifice 81 outside the double tube kept at 25 ° C. using a cylindrical double tube orifice, and the circular orifice inside the double tube was discharged. From 82, a mixed liquid having a mass ratio of 25/75 methanol / water at 25 ° C. pressurized to 0.15 MPa was discharged. In the present embodiment, a double-tube orifice having a size of the outer diameter D1 = 0.6 mm, the outer diameter D2 = 0.5 mm, and the inner diameter D3 = 0.4 mm in FIG. 8 was used. The dope discharged from the orifice entered a coagulation liquid consisting of a mixed solution of the same mass of methanol / water at 25 ° C. through an air gap of 10 mm while being drawn at a constant speed, and became coagulated yarn. The obtained polyketone coagulated yarn was washed with a mixed solution of the same mass of methanol / water and wound up in a skein. Subsequently, after skein was wound, it was replaced with acetone, further substituted with normal hexane, and then dried at 50 ° C. to obtain a hollow fiber membrane.

  The obtained hollow fiber membrane had a thickness of 36 μm, an outer diameter of 220 μm, a hollowness of 45%, a maximum pore diameter of 0.16 μm, and a porosity of 66%. The dense layer exists in the innermost layer, the ratio of the dense layer thickness to the non-dense layer thickness is 17:83, the proportion of the fibrous structure having a thickness of 0.5 μm or less in the dense layer is 95%, and the tensile strength is 5.1 MPa. Met. The polyketone porous film was uniform with no large pores, such as pinholes, observed.

The performance as a filtration membrane was evaluated using the polyketone hollow fiber membrane. The pressure loss per unit thickness when the water filtration rate was 1.4 mL / min / cm ² was measured and found to be 10.0 kPa. Further, when a polystyrene latex aqueous dispersion having an average particle size of 0.05 μm was filtered for 10 minutes, the particle collection efficiency was 97%. Thus, the polyketone porous membrane obtained in Example 1 was very excellent as a filter medium. The results are shown in Table 2.

[Example 18]
A polyketone hollow fiber membrane was produced under the same conditions as in Example 17 except that the polymer concentration was 12% by mass. The results are shown in Table 2.

[Comparative Example 5]
A polyketone hollow fiber membrane was produced under the same conditions as in Example 16 except that the coagulating liquid and the cleaning liquid were mixed in a methanol / water mass ratio of 60/40.

  The obtained hollow fiber membrane had a thickness of 96 μm, an outer diameter of 469 μm, a hollowness of 37%, a maximum pore diameter of 0.25 μm, and a porosity of 80%. The dense layer is present in the outermost layer, the ratio of the dense layer thickness to the non-dense layer thickness is 0.5: 99.5, the proportion of the fibrous structure having a thickness of 0.5 μm or less in the dense layer is 95%, and the tensile strength Was 1.3 MPa. The polyketone porous film was uniform with no large pores, such as pinholes, observed.

The performance as a filtration membrane was evaluated using the polyketone hollow fiber membrane. The pressure loss per unit thickness when the water filtration rate was 1.4 mL / min / cm ² was measured and found to be 0.2 kPa. Further, when a polystyrene latex aqueous dispersion having an average particle size of 0.05 μm was filtered for 10 minutes, the particle collection efficiency was 14%, which was not a satisfactory value. The results are shown in Table 2.

[Example 19]
While cooling the polyketone porous film obtained in Example 3 with dry ice, an electron beam of 200 kGy was irradiated for several seconds to produce a radicalized polyketone porous film. The radicalized polyketone porous membrane was immersed in a 5% by mass vinylbenzyltrimethylammonium chloride aqueous solution from which dissolved oxygen was removed by nitrogen bubbling at 60 ° C. for 3 hours in a nitrogen atmosphere. Next, after thoroughly washing with water and acetone in this order, the mixture was dried at 60 ° C. to obtain a quaternary ammonium polyketone porous membrane. The porous quaternary ammonium polyketone membrane was very hydrophilic and maintained its original structure and flow-pressure loss characteristics. Furthermore, the polyketone porous membrane had an excellent anion exchange ability.

[Example 20]
The polyketone porous film obtained in Example 3 was immersed in a 10 mass% glycine methyl ester / acetic acid suspension at 120 ° C. for 5 minutes. Next, the polyketone porous film was taken out and immersed in a 1 mass% sodium hydroxide aqueous solution at 80 ° C. for 10 minutes. Next, the polyketone porous membrane was taken out, washed thoroughly with water, methanol and acetone in this order, and then dried at 60 ° C. to prepare a polyketone porous membrane containing N- (carboxymethyl) pyrrole component. The carboxylated polyketone porous membrane was very hydrophilic and maintained its original structure and flow-pressure loss characteristics. Furthermore, the polyketone porous membrane had excellent cation exchange ability.

[Example 20, Comparative Example 6 and Comparative Example 7]
Each of the polyketone porous membranes obtained in Example 3, Comparative Example 3 and Comparative Example 4 was used as a separator, and a single-layer laminated lithium ion battery was produced by a general method. The resistance was evaluated. For the positive electrode, an aluminum foil coated with a composition of lithium cobalt acid / acetylene black / polyvinylidene fluoride = 89/5/6 (mass ratio) (area 14 mm × 21 mm, thickness 83 μm) was used. . For the negative electrode, a copper foil coated with a composition of mesocarbon microbeads / acetylene black / polyvinylidene fluoride = 93/2/5 (mass ratio) (area 15 mm × 21 mm, thickness 83 μm) is used It was. As the electrolytic solution, a solution of lithium hexafluorophosphate dissolved in a solution of ethylene carbonate / methyl ethyl carbonate = 30/70 (mass ratio) at a concentration of 1 mol / L was used. The initial cycle characteristics were evaluated under the conditions of temperature: 25 ° C., charge: 0.2 C, 4.2 V, CCCV 8 h, discharge: 0.2 C, 2.7 V, CC. Table 3 shows the results of charge / discharge capacity and efficiency in the first and third cycles. From these results, it was found that the charge / discharge efficiency in the third cycle was high at about 99%. Also, no abnormalities such as short circuit were observed from the charge / discharge curve, and it was found that an excellent lithium ion battery was produced. Next, the AC impedance characteristics were evaluated under the conditions of temperature: 25 ° C., frequency: 0.1 to 20,000 Hz, and amplitude: 10 mV. Table 3 shows a resistance value of 20,000 Hz. The smaller the resistance value, the lower the resistance of the separator, and the better the output performance. In the example using the polyketone porous film of Example 3 and Comparative Example 3, the resistance was as low as 0.5Ω or less, but in the example using the polyketone porous film of Comparative Example 4, a high value was shown. In addition, each polyketone porous membrane of each polyketone porous membrane was used in an environment of 23 ° C. and 50% relative humidity according to JIS C 2110-1, using an AC / DC withstand voltage tester TW-5110ADLP (manufactured by Tama Densetsu Co., Ltd.) The withstand voltage was measured. The results are shown in Table 3. The example using the polyketone porous film of Example 3 and Comparative Example 4 had a withstand voltage of 1.5 V or more and high insulation, but the example using the polyketone porous film of Comparative Example 3 had a low withstand voltage. Met. Therefore, the example using the polyketone porous film of Example 3 showed excellent performance in which both high insulation and low resistance were compatible.

  Since the polyketone porous membrane of the present invention has high heat resistance and chemical resistance derived from polyketone, and has a high porosity and a specific porous structure by a combination of a dense layer and a non-dense layer, a filter medium and a battery It is useful as a separator for capacitors and the like. The filter medium is useful as a filter for water treatment, membrane bioreactor, industrial liquid filtration, deaeration, gas dust removal, chemical filter, and medical use. It is useful as a separator for a secondary battery and a capacitor separator such as an electrolytic capacitor, an electric double layer capacitor, or a lithium ion capacitor. Further, the polyketone porous membrane can be used as an immunochromatographic developing phase and a cell culture scaffold.

DESCRIPTION OF SYMBOLS 11 Dense layer 12 Non-dense layer 13 Polyketone porous membrane surface 21 Polyketone part 22 Polyester fiber part 23 Polyketone part 31 Hollow fiber membrane 32 Hollow fiber membrane cross-section 33 Void 41, 51, 61 Polyketone part 42, 52 Non-woven part 53, 63 Composite part 81 Circular orifice 82 Circular orifice 83 Double pipe orifice

Claims (18)

A polyketone porous membrane containing 10 to 100% by mass of a polyketone, which is a copolymer of carbon monoxide and one or more olefins, under the following conditions (1) to (3):
(1) The maximum pore size of the polyketone porous membrane is 1 μm or less;
(2) The porosity of the polyketone porous membrane is 5 to 90%; and (3) the polyketone porous membrane has a polyketone portion formed only by the polyketone over the film thickness direction. , have a more than 80% polymer fill ratio, and the dense layer that consists of fibrous tissue, and a non-dense layer having a polymeric fill ratio less than 80%, the thickness T1 and the non-dense layer of the dense layer The ratio T1: T2 to the thickness T2 is 1:99 to 50:50;
Satisfying the polyketone porous membrane. The polyketone is represented by the following general formula (1):
{In the formula, R represents a substituted or unsubstituted hydrocarbon group having 2 to 20 carbon atoms. } The polyketone porous film of Claim 1 containing the repeating unit represented by these. The following formula (2) with respect to the repeating unit constituting the polyketone:
The polyketone porous membrane according to claim 1 or 2, wherein the proportion of the 1-oxotrimethylene repeating unit represented by the formula is 70 mol% or more.   In the general formula (1), R is hydrogen, halogen, hydroxyl group, ether group, primary amino group, secondary amino group, tertiary amino group, quaternary ammonium group, sulfonic acid group, sulfonic acid ester group, carvone. 4 or 3 including one or more functional groups selected from the group consisting of an acid group, a carboxylic acid ester group, a phosphoric acid group, a phosphoric acid ester group, a thiol group, a sulfide group, an alkoxysilyl group, and a silanol group. The polyketone porous membrane described in 1.   The repeating unit represented by the general formula (1) with respect to the repeating unit constituting the polyketone, wherein R is a hydroxyl group, an ether group, a primary amino group, a secondary amino group, a tertiary amino group, or a quaternary ammonium group. One or more selected from the group consisting of sulfonic acid groups, sulfonic acid ester groups, carboxylic acid groups, carboxylic acid ester groups, phosphoric acid groups, phosphoric ester groups, thiol groups, sulfide groups, alkoxysilyl groups, and silanol groups The polyketone porous membrane according to any one of claims 2 to 4, wherein the ratio of the repeating unit containing the functional group is in the range of 0.1 to 30 mol%. The polyketone is represented by the following general formula (3):
{In the formula, R ¹ , R ² , and R ³ are each independently hydrogen, halogen, an alkyl group having 1 to 20 carbon atoms, a hydroxyl group, an ether group, a primary amino group, a secondary amino group, or a tertiary amino group. Group consisting of a group, a quaternary ammonium group, a sulfonic acid group, a sulfonic acid ester group, a carboxylic acid group, a carboxylic acid ester group, a phosphoric acid group, a phosphoric acid ester group, a thiol group, a sulfide group, an alkoxysilyl group, and a silanol group It is a substituent containing one or more functional groups selected from. } The polyketone porous membrane of any one of Claims 1-5 which is a copolymer containing the structure represented by 30 mass% or less. The polyketone porous membrane according to claim 6, wherein R ¹ and R ^{2 in the} general formula (3) are both hydrogen.   The polyketone porous membrane according to any one of claims 1 to 7, further comprising at least one nonwoven fabric combined with the polyketone.   The nonwoven fabric is made of thermoplastic synthetic fiber, and the nonwoven fabric layer (A) having a fiber diameter of 5 to 20 μm and the nonwoven fabric layer (B) having a fiber diameter of 0.5 to 4 μm are A / B / A type Or the polyketone porous film of Claim 8 which is what was combined and integrated by A / B type.   The polyketone porous membrane according to any one of claims 1 to 9, which is in the form of a flat membrane.   The polyketone porous membrane according to any one of claims 1 to 9, which is a hollow fiber membrane having one or more voids penetrating in the longitudinal direction.   The filter for filtration containing the polyketone porous membrane of any one of Claims 1-11.   The filter according to claim 12, which is a filter for water treatment, a filter for membrane bioreactor, a filter for industrial liquid filtration, a filter for deaeration, a filter for gas dust removal, a filter for chemical filter, a filter for gas separation, or a medical filter. Filter for filtration.   A separator for a lithium ion secondary battery, comprising the polyketone porous film according to claim 10.   A capacitor separator comprising the polyketone porous film according to claim 10.   The capacitor separator according to claim 15, wherein the capacitor is an electrolytic capacitor, an electric double layer capacitor, or a lithium ion capacitor.   A developing phase for immunochromatography comprising the polyketone porous membrane according to claim 10.   A scaffold for cell culture, comprising the polyketone porous membrane according to claim 10.