JP2009297641A - Braid-consolidated hollow fiber membrane - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a braid-consolidated hollow fiber membrane with high pressure resistance even in high pressure liquid, keeping the form of the membrane, causing no dimensional change in an organic solvent liquid of high temperature, and securing dimensional stability of the membrane. <P>SOLUTION: In the braid-consolidated hollow fiber membrane formed with an activated layer on the surface of the tubular braid, the braid is formed by mixing and braiding metallic wires and polymer fibers. The hollow fiber membrane can be used for a separation process in a high pressure owing to its pressure resistance, used for separation of the organic solvent at high temperature owing to its dimensional stability, and also is applicable to various application fields owing to its conductivity. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a blade-reinforced hollow fiber membrane.

  In order to use the hollow fiber membrane under high pressure, it is necessary to ensure the mechanical stability of the membrane against external pressure, and in order to use the hollow fiber membrane in a high temperature organic solvent liquid, the dimensions of the membrane Stability is required. In order to increase the stability of the membrane against external pressure, there is a method of increasing the thickness of the membrane and lowering the porosity, which causes a new problem of reducing the liquid permeation rate through the membrane. For this reason, various attempts have been made to reinforce the active layer membrane of the hollow fiber membrane with a tubular blade.

  Conventionally, hollow fiber membranes used mainly in membrane separation processes for treating non-solvent solutions at normal temperatures, such as wastewater treatment and biological membrane reaction processes, are braided into a tubular shape using only polymer fibers. The active layer film was formed on the outer surface. In general, fibers such as polyester, nylon, aramid, polypropylene, and polyethylene are used as the polymer fibers used for knitting the blade, and a suitable polymer fiber material is selected according to the intended use. . Glass fiber may be used for manufacturing a blade of a hollow fiber type separation membrane used in a high temperature separation membrane process. The thickness and inner diameter of the blade are determined according to the type of fiber used, the thickness of the unit filament constituting the yarn (denier), the number of filaments, and the number of yarn streaks used for knitting.

  The above-mentioned conventional polymer fiber blade reinforced hollow fiber membrane has a characteristic with respect to the load in the longitudinal direction of the membrane, that is, the tensile strength of the membrane is extremely excellent, but the load acting perpendicular to the membrane surface, that is, in the radial direction. With respect to pressure, the resistance (pressure resistance) is extremely weak, and when the radial pressure increases, there is a disadvantage that the film tends to lose its original shape. For example, when a polymer fiber blade reinforced hollow fiber membrane is used in a reverse osmotic pressure membrane separation process at a pressure of 20 atm or higher, the active layer membrane cannot maintain a circular cross-sectional tube shape, and the cross-sectional shape is increased by pressure Will be distorted.

  In general, it is extremely difficult for an active layer film made of a polymer material to have dimensional stability against a high-temperature organic solvent. However, the above-described conventional polymer fiber blade reinforced hollow fiber membrane changes not only the active layer membrane but also the size of the blade itself under a high temperature organic solvent liquid. As described above, when the dimensional stability is lost, a considerable stress is generated at the interface between the blade and the active layer, and the active layer film is damaged.

  As a result, conventional polymer fiber blade reinforced hollow fiber membranes have no drawbacks in use for low pressure, room temperature, non-solvent liquids, but are difficult to use for high pressure liquids or high temperature organic solvent liquids. There is.

  For this reason, the active layer film is applied to the blade used as a reinforcing material, and this blade mainly bears not only the mechanical load (high pressure) but also the dimensional change due to exposure to high temperature organic solvent. Therefore, improvement of the blade is desired for the form stability and dimensional stability.

  Therefore, the present invention has been made in view of such problems, and the object thereof is to have a high pressure resistance even in a high-pressure liquid and to maintain the form of the film, and in a high-temperature organic solvent liquid, It is an object of the present invention to provide a new and improved blade-reinforced hollow fiber membrane that does not change in dimensions and can ensure the dimensional stability of the membrane.

  In order to solve the above problems, according to an aspect of the present invention, in a hollow fiber membrane in which an active layer membrane is formed on the surface of a tubular blade, the blade is knitted by mixing a metal wire and a polymer fiber. There is provided a blade-reinforced hollow fiber membrane that improves the dimensional stability of the membrane against an organic solvent and the morphological stability of the membrane against an external pressure in the radial direction, and imparts conductivity to the membrane.

  The metal wire may be one or more metal wires selected from a copper wire, a nickel wire, a stainless steel wire, a tin wire or a nichrome wire.

  The metal wire may have a diameter of 0.05 mm to 0.40 mm.

  The polymer fiber may be one or more fibers selected from polyester, nylon, aramid, polypropylene, or polyethylene.

  The polymer fiber may be a yarn in which 10 to 400 single filament fibers having a thickness of 100 to 500 denier are combined to form a single line.

  The total number of bars of the polymer fiber and the metal wire used for the blade knitting may be 10 to 80 bars.

  The metal wire may be formed by combining with the polymer fiber in advance before knitting to form a single line, or a single line formed only by the metal wire.

  The thickness of the metal line in which a single line is formed only by the metal line may be larger than the thickness of the metal line combined with the polymer fiber.

  The number of the metal wire reinforcing bars used for knitting may be 5 to 30% with respect to the total number of knitting yarn reinforcing bars.

  Each metal wire in the blade may be knitted while maintaining an equal interval with the adjacent metal wire.

  According to the present invention, a hollow fiber membrane can be used for a separation process under high pressure due to an improvement in pressure resistance of the membrane, and a hollow fiber membrane can be used for organic solvent separation under a high temperature due to an improvement in dimensional stability of the membrane. Can be used. Furthermore, the hollow fiber membrane can be applied to various application fields due to the conductivity of the membrane.

  Exemplary embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In addition, in this specification and drawing, about the component which has the substantially same function structure, duplication description is abbreviate | omitted by attaching | subjecting the same code | symbol.

  In the present invention, a hollow fiber membrane can be used for a high-pressure liquid or a high-temperature organic solvent liquid by forming a braided blade by mixing and knitting metal wires and polymer fibers and forming an active layer on the outer surface thereof. The present invention relates to a metal wire mixed blade reinforced hollow fiber membrane.

  The present invention is characterized in that, in a hollow fiber membrane in which an active layer is formed on the surface of a tubular blade, the blade is knitted by mixing a metal wire and a polymer fiber.

  The metal wire is preferably one or more metal wires selected from a copper wire, a nickel wire, a stainless steel wire, a tin wire or a nichrome wire. Moreover, it is preferable that the diameter of the said metal wire is 0.05 mm-0.40 mm, for example.

  As described above, the hollow fiber membrane used in the high-pressure liquid particularly needs mechanical stability, and the hollow fiber membrane used in the high-temperature organic solvent particularly needs dimensional stability.

  It is difficult to ensure the mechanical strength and dimensional stability of the active layer film itself, and when the active layer is reinforced only with polymer fiber blades, it is vulnerable to high pressure, high temperature and contact with organic solvents. Because there are points, it is necessary to supplement the physical properties of the blade. From this point of view, metal wires not only have much better mechanical properties than polymer fibers, but also have no heat resistance and compatibility with organic solvent liquids when in contact with organic solvents. Excellent in dimensional stability.

  When a part of the polymer fiber constituting the blade is replaced with a metal wire, the stability of the blade against pressure, temperature and contact with an organic solvent is determined by the metal wire which is a main reinforcing material. As a result, blades made by mixing metal wires and polymer fibers are extremely stable even under high temperature, high pressure, or organic solvent contact conditions, so membranes reinforced with such blades are also , Become stable.

  When manufacturing blades by mixing metal wires and polymer fibers, the mechanical properties and dimensional stability of the blades improve as the proportion of metal wires increases, but the blades themselves become crisp, When the active layer film is applied and when the module is manufactured, the handleability deteriorates. Conversely, when the proportion of the metal wire is lowered, the fluidity of the blade is increased and the handleability is good, but the mechanical properties and dimensional stability are weakened. For this reason, it is preferable that the number of metal wires used for knitting is, for example, 5 to 30% with respect to the total number of knitting yarns used for knitting. If necessary, the metal wire can be combined with the polymer fiber, or only the metal wire can be wound around the bobbin and used for knitting. Here, when only the metal wire is wound around the bobbin, it is preferable to use a metal wire that is much thicker than when wound with the polymer fiber. It is possible to use a single metal wire as the metal wire, or it is possible to use an aggregate metal wire in which 2 to 5 thin metal wires are combined into a single line.

  The polymer fibers are preferably selected from, for example, polyester, nylon, aramid, polypropylene, or polyethylene fibers. As the polymer fiber, for example, a yarn in which fibers of a single filament having a thickness of 100 to 500 denier are combined, for example, 10 to 400 lines can be used.

  The blade knitting preferably uses, for example, 10 to 80 braided yarn (polymer fiber and metal wire).

  On the outer surface of the blade of the present invention having the above-described configuration, a porous microfiltration membrane or an ultrafiltration membrane can be formed as an active layer membrane. The porous microfiltration membrane or ultrafiltration membrane is selected from, for example, polysulfone, polyethersulfone, polyimide, polyetherimide, polyacrylonitrile, polyethylene terephthalate, polybutylene terephthalate, nylon, polyphenylsulfate, polyethylene or polypropylene The obtained polymer is dissolved in each solvent, or mixed with a diluent at a high temperature to form a uniform solution, which is applied onto the blade, and then a known diffusion-induced phase separation method or heat-induced phase separation method. To a certain thickness.

  On the porous microfiltration membrane or ultrafiltration membrane, for example, a nano-permeable membrane, reverse osmotic pressure membrane, vapor permeable membrane, permeable evaporation membrane or gas permeable membrane in the form of a composite membrane coated with a thin active layer Etc. may be further formed.

  The hollow fiber membrane produced in this way can maintain excellent shape stability and dimensional stability even when used in a high-pressure liquid or a high-temperature organic solvent.

  1A is a partially cut perspective view of a blade-reinforced hollow fiber membrane according to the first embodiment of the present invention, FIG. 1B is a cross-sectional view of the blade-reinforced hollow fiber membrane shown in FIG. 1A, and FIG. 1B is a layout diagram of a metal wire bobbin and a polymer fiber bobbin during blade braiding shown in FIG. 1A. FIG. 2A is a partially cut perspective view of a blade-reinforced hollow fiber membrane according to a second embodiment of the present invention, and FIG. 2B is a cross-sectional view of the blade-reinforced hollow fiber membrane shown in FIG. 2A. FIG. 2B is a layout diagram of a metal wire bobbin and a polymer fiber bobbin during blade braiding shown in FIG. 2A.

  The blade-reinforced hollow fiber membrane according to the first embodiment shown in FIG. 1A and FIG. 1B is obtained by knitting a blade by mixing 2 bars of metal wire 3 and 34 bars of polymer fiber 5 and then activating the outer surface thereof. 2 is a blade-reinforced hollow fiber membrane formed with a layer 1. The blade-reinforced hollow fiber membrane according to the second embodiment shown in FIGS. 2A and 2B is a mixture of 4 lines of metal wire 3 and 32 lines of polymer fiber 5. Then, after braiding the blade, the blade-reinforced hollow fiber membrane is formed with the active layer 1 on the outer surface thereof.

  That is, in the blade-reinforced hollow fiber membrane according to the first embodiment of the present invention, as shown in FIGS. 1A and 1B, two metal wires 3 and 34 polymer fibers 5 are knitted in a mesh shape. And an active layer 1 formed on the blade. In addition, the blade-reinforced hollow fiber membrane according to the second embodiment of the present invention, as shown in FIG. 2A and FIG. 2B, braids four metal wires 3 and 32 polymer fibers 5 into a mesh shape. And an active layer 1 formed on the blade.

  Referring to FIG. 1A and FIG. 1B or FIG. 2A and FIG. 2B, the hollow fiber membrane according to each embodiment of the present invention has pressure resistance even in a high-pressure liquid, and the dimensions of the membrane also in a high-temperature organic solvent liquid. In order to prevent the change, a part of the polymer fiber 5 is replaced with the metal wire 3, and the blade is knitted.

  FIG. 1A and FIG. 1B or FIG. 2A and FIG. 2B exemplify a case where a single strand of polymer fiber is composed of a single filament and a single strand of metal wire is composed of a single metal wire. As described above, a yarn can be used as the polymer fiber, and a collective metal wire can be used as the metal wire.

  Referring to FIG. 1C or 2C, the thickness of the blade is determined by, for example, the thickness of the polymer fiber streak and the thickness of the metal wire streak. In order to manufacture a blade having a uniform thickness, it is preferable that the thickness of the polymer fiber streak used matches the thickness of the metal wire streak.

  As described above, for example, 10 to 80 knitting yarns (polymer fibers and metal wires) are used for knitting the blades according to the embodiments of the present invention. After the polymer fiber and the metal wire are wound around the bobbin, as shown in FIGS. 1C and 2C, this is installed on the annular carrier 11 of the knitting machine. At this time, the number of polymer fiber bobbins 9 to be installed and the number of polymer fiber bars used for knitting, and the number of metal wire bobbins 7 and the number of metal wire bars used for knitting coincide with each other. For this reason, the ratio of the metal wire in the blade is represented by the ratio of the number of metal wire bobbins to the total number of bobbins. For example, when the total number of bobbins is 36 and the number of metal wire bobbins is 3, among these, the proportion of metal wires is 8.33%. As described above, in order to maintain the ratio of the number of metal wires to the total number of knitting yarns to about 5 to 30%, the metal (metal wire combined with the polymer fiber) installed on the knitting machine carrier 11 is maintained. The number of bobbins 7 is preferably maintained at a ratio of, for example, 5 to 30% with respect to the total number of bobbins.

  It is preferable that each metal wire in the blade is knitted while maintaining equal intervals with adjacent metal wires. For this purpose, as shown in FIG. 1C or FIG. 2C, when the metal wire bobbins are installed on the carrier, they are arranged so as to be symmetrical with respect to the carrier circular center according to the number. If the metal wire bobbins are arranged out of symmetry, the surface of the braided blade is neither smooth nor uniform.

  A blade-reinforced hollow fiber membrane can be manufactured by forming a desired active layer 1 on a blade surface manufactured by mixing metal wires and polymer fibers at a certain ratio. When forming a microfiltration membrane or an ultrafiltration membrane as the active layer 1, for example, polysulfone, polyethersulfone, polyimide, polyetherimide, polyacrylonitrile, polyethylene terephthalate, polybutylene terephthalate, nylon, polyphenylsulfate, Polyethylene or polypropylene is dissolved in a solvent, or mixed with a diluent at high temperature to produce a homogeneous solution, which is applied to the outer surface of the blade and then a known common phase transition method, ie diffusion induced phase separation A porous polymer membrane having a certain thickness is formed by the method or the thermally induced phase separation method.

  On the microfiltration membrane or ultrafiltration membrane, for example, a nano-permeable membrane, reverse osmotic pressure membrane, vapor permeable membrane, permeable evaporation membrane or gas permeable membrane is further formed in the form of a thin active layer composite membrane. Also good.

  Below, the Example by this invention is explained in full detail, and the property is compared with the conventional polymeric fiber braid | blade reinforcement | strengthening hollow fiber membrane.

<First embodiment>
A braid was manufactured by mixing and knitting 34 pieces of 300/150 polyester yarn and 2 pieces of stainless steel wire having a diameter of 0.2 mm. At this time, the outer diameter was 2 mm and the inner diameter was 1 mm. Polysulfone (500 g) and polyvinylpyrrolidone (130 g) are dissolved in dimethylacetamide (1370 g) to produce a uniform solution, which is uniformly coated on the outer surface of the blade mixed with metal wires, and then solidified in water to be porous. A blade reinforced hollow fiber membrane having an active layer membrane was produced.

<Second Embodiment>
A braid was manufactured by mixing and knitting 32 300/150 polyester yarns and 4 0.2 mm diameter stainless steel wires. At this time, the outer diameter was 2 mm and the inner diameter was 1 mm. Polysulfone (500 g) and polyvinylpyrrolidone (130 g) are dissolved in dimethylacetamide (1370 g) to produce a uniform solution, which is uniformly coated on the outer surface of the blade mixed with metal wires, and then solidified in water to be porous. A blade reinforced hollow fiber membrane having an active layer membrane was produced.

<Comparative example>
A braid was produced by knitting 36 300/150 polyester yarns. At this time, the outer diameter was 2 mm and the inner diameter was 1 mm. A blade having a porous active layer film prepared by dissolving 500 g of polysulfone and 130 g of polyvinyl pyrrolidone in 1370 g of dimethylacetamide to produce a uniform solution, which is uniformly coated on the outer surface of the polyester blade and then solidified in water. A reinforced hollow fiber membrane was produced.

  After drying, after measuring the length of the produced active layer membrane, each hollow fiber membrane was put in ethanol and normal hexane, allowed to stand at 50 ° C. for 24 hours, and then measured for length to evaluate dimensional stability. Also, a module was manufactured with each manufactured membrane, and water at 10, 20, and 40 atmospheres was added to the outside of the hollow fiber membrane incorporated in the module, and the cross-sectional change of the hollow fiber membrane in the module was observed. .

  The hollow fiber membrane (comparative example) reinforced with a blade not containing a metal wire has a length increased by 2.5% to 4.3% due to swelling in an organic solvent, and is pressurized. It was observed that the cross section of the film was distorted above 20 atm. On the other hand, the metal wire mixed blade reinforced hollow fiber membranes according to the present invention (first embodiment, second embodiment) exhibit excellent dimensional stability in an organic solvent, and up to 40 atm. It was observed that a stable film form was maintained even under the pressure of. The above results indicate that the metal wire contained in the blade increases the dimensional stability of the film against organic solvents and increases the morphological stability against pressure.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to this example. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Understood.

1 is a partially cut perspective view of a blade-reinforced hollow fiber membrane according to a first embodiment of the present invention. 1B is a cross-sectional view of the blade-reinforced hollow fiber membrane shown in FIG. 1A. FIG. 1B is a layout diagram of a metal wire bobbin and a polymer fiber bobbin during blade braiding shown in FIG. 1A. FIG. It is a partial cutaway perspective view of the braid | blade reinforcement | strengthening hollow fiber membrane which concerns on the 2nd Embodiment of this invention. It is sectional drawing of the braid | blade reinforcement | strengthening hollow fiber membrane shown to FIG. 2A. FIG. 2B is a layout diagram of the metal wire bobbin and the polymer fiber bobbin during blade braiding shown in FIG. 2A.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Active layer film 3 Metal wire 5 Polymer fiber 7 Metal wire bobbin 9 Polymer fiber bobbin 11 Bobbin carrier

Claims (10)

In the hollow fiber membrane in which the active layer membrane is formed on the surface of the tubular blade,
The blade is knitted by mixing metal wires and polymer fibers,
A blade-reinforced hollow fiber membrane characterized by improving membrane dimensional stability against an organic solvent and morphological stability of the membrane against an external pressure in the radial direction and imparting conductivity to the membrane.   The blade according to claim 1, wherein the metal wire is one or more metal wires selected from a copper wire, a nickel wire, a stainless steel wire, a tin wire or a nichrome wire. Reinforced hollow fiber membrane.   The blade-reinforced hollow fiber membrane according to claim 1 or 2, wherein the metal wire has a diameter of 0.05 mm to 0.40 mm.   The blade reinforcement according to any one of claims 1 to 3, wherein the polymer fiber is one or more fibers selected from polyester, nylon, aramid, polypropylene, or polyethylene. Hollow fiber membrane.   5. The yarn according to claim 1, wherein the polymer fiber is a yarn formed by combining 10 to 400 single filament fibers having a thickness of 100 to 500 denier to form a single line. The blade reinforced hollow fiber membrane according to 1.   The blade-reinforced hollow fiber membrane according to any one of claims 1 to 5, wherein the total number of streaks of the polymer fiber and the metal wire used in the blade knitting is 10 to 80 streaks.   The said metal wire combined with the said polymer fiber in advance before knitting to form a single line, or formed only a single line with the metal wire. A blade-reinforced hollow fiber membrane according to claim 1.   8. The blade-reinforced hollow fiber according to claim 7, wherein a thickness of the metal wire in which a single line is formed only by the metal wire is larger than a thickness of the metal wire combined with the polymer fiber. film.   The blade-reinforced hollow fiber membrane according to any one of claims 1 to 8, wherein the number of metal wire reinforcing bars used for knitting is 5 to 30% with respect to the total number of knitting yarn reinforcing bars. The blade-reinforced hollow fiber membrane according to any one of claims 1 to 9, wherein each metal wire in the blade is knitted while maintaining an equal interval with the adjacent metal wire.

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