JP2018023971A - Flow passage material and separation membrane element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flow passage material and a separation membrane element for realizing a high fluid passing speed.SOLUTION: A separation membrane element 1 comprises a catchment pipe 6 and a separation membrane body 3 wound around the catchment pipe 6. The separation membrane element 1 also comprises a supply-side flow passage material 2 and a member such as an end plate. A permeation-side flow passage material 4 is positioned so as to face a permeation-side surface of the separation membrane body 3, and is wound around the catchment pipe 6 together with the separation membrane body 3. Here, the permeation-side flow passage material 4 desirably has a static water contact angle of 125 degrees or greater, and desirably a surface area of 125 degrees or more occupies 80% or more an overall area. In addition, fluorine preferably exists as a constituent element of a surface.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a flow path material that forms a flow path for fluid such as liquid and gas, and a separation membrane element using the flow path material.

  A technique for separating components contained in a fluid such as liquid and gas with high efficiency has attracted industrial attention. In particular, in technology for removing ionic substances contained in seawater, brine, and the like, in recent years, the use of separation methods using separation membrane elements has been expanded as a process for saving energy and resources. Separation membrane bodies used for separation methods using separation membrane elements are classified into microfiltration membranes, ultrafiltration membranes, nanofiltration membranes, reverse osmosis membranes, and forward osmosis membranes in terms of their pore sizes and separation functions. These membranes are used, for example, in the production of drinking water from seawater, brackish water and water containing harmful substances, industrial ultrapure water, wastewater treatment and recovery of valuable materials. It is properly used depending on the separation component and separation performance.

  Although there are various forms as the separation membrane element, they are common in that the supply water is supplied to one surface of the separation membrane body and the permeated water is obtained from the other surface. The separation membrane element includes a large number of bundled separation membrane bodies so that the membrane area per separation membrane element is increased, that is, the amount of permeated water obtained per separation membrane element is large. It is formed to be large. As the separation membrane element, various shapes such as a spiral type, a hollow fiber type, a plate-and-frame type, a rotating flat membrane type, and a flat membrane integrated type have been proposed according to applications and purposes.

  For example, spiral separation membrane elements are widely used for reverse osmosis filtration. The spiral separation membrane element includes a center tube and a laminate wound around the center tube. The laminate includes a supply-side channel material that supplies supply water (that is, treated water) to the surface of the separation membrane body, a separation membrane body that separates components contained in the supply water, and a permeation through the separation membrane body. It is formed by laminating permeate-side flow path materials for guiding the separated permeated water to the central tube. The spiral separation membrane element is preferably used in that a large amount of permeated water can be taken out because pressure can be applied to the supplied water.

  In the spiral type separation membrane element, in general, a polymer net is mainly used as a supply-side channel material in order to form a supply-side water channel. In addition, a laminated type separation membrane body is used as the separation membrane body. The laminate type separation membrane body is composed of a separation functional layer (porous support layer) made of a crosslinked polymer such as polyamide, a porous resin layer made of a polymer such as polysulfone, polyethylene terephthalate, which is laminated from the supply side to the permeation side. A non-woven substrate made of a polymer such as Further, as the permeation side channel material, a knitted member called a tricot having a smaller interval than the supply side channel material is used for the purpose of preventing the separation membrane main body from dropping and forming the permeation side channel. .

  In recent years, due to the increasing demand for reducing the fresh water generation cost, there has been a demand for higher performance of the separation membrane element. For example, in order to improve the separation performance of the separation membrane element and increase the amount of permeated water per unit time, it has been proposed to improve the performance of the separation membrane element member such as each flow path member.

  Specifically, Patent Document 1 proposes a permeation-side flow channel material that is formed with irregularities. Patent Document 2 proposes a central tube in which the distance between the communication holes is controlled. Further, Patent Document 3 proposes a supply-side flow path material formed by a fusion method in which the weft is thinned and the warp is meandered.

JP 2006-247453 A JP 2014-140840 A Japanese Patent No. 4688140

  Despite the various proposals described above, the channel material is not sufficient in terms of fluid passage speed and has room for improvement. Then, an object of this invention is to provide the flow-path material which implement | achieves a high fluid passage speed.

  In order to achieve the above object, the present invention comprises the following configurations (1) to (8).

  (1) A channel material having a surface with a static water contact angle of 125 degrees or more.

(2) A surface having a static water contact angle of 125 degrees or more occupies 80% or more of the total surface area.
The flow path material according to (1) above.

(3) Fluorine is present as a constituent element on the surface,
The flow path material according to (1) or (2) above.

  (4) The flow path material according to any one of (1) to (3), which is used for a separation membrane element.

  (5) The flow path material according to (4), wherein the separation membrane element is a spiral type.

(6) A separation membrane element comprising a water collecting pipe, a separation membrane body comprising a supply-side surface and a permeation-side surface, a supply-side flow passage material, and a permeation-side flow passage material,
A separation membrane element using the channel material according to any one of (1) to (3) above in at least one of the supply side channel material and the permeation side channel material.

(7) A permeation-side flow path member provided to face the permeation-side surface of the separation membrane main body and having a sheet and a plurality of protrusions fixed on the sheet,
The separation membrane element according to (6) above.

(8) The protrusion is continuous in a direction perpendicular to the longitudinal direction of the water collecting pipe,
The separation membrane element according to (6) or (7) above.

(9) The permeation-side flow path material includes an open area by a through hole in the thickness direction and other non-open areas, and the non-open area includes a plurality of fine protrusions.
The separation membrane element according to (6) above.

(10) The fine protrusions have a thickness of 5 μm or less and a number density of 20 pieces / mm ² or more and 1000 pieces / mm ² or less.
The separation membrane element according to (9) above.

  According to the present invention, it is possible to form a flow path that suppresses the flow resistance of the fluid, and it is possible to obtain a flow path material that realizes a high fluid passage speed.

  By applying this flow path material to the separation membrane element, it is expected that the operation with a large amount of permeated water will be continued in the desalination of brine and seawater.

The partial expansion perspective view which shows the outline | summary of a separation membrane element. The top view which shows an example of the supply side flow-path material which is one Embodiment of this invention. Sectional drawing which shows an example of the permeation | transmission side channel material which is one Embodiment of this invention. Sectional drawing which shows the other example of the permeation | transmission side channel material. Sectional drawing which shows the further another example of the permeation | transmission side channel material. The top view which shows the further another example of the permeation | transmission side channel material. The top view which shows the further another example of the permeation | transmission side channel material. Sectional drawing which shows an example of a separation membrane main body. Sectional drawing which shows the other example of a separation membrane main body.

  Hereinafter, an embodiment of the present invention will be described in detail.

[1. (Channel material)
The channel material is a member that forms a channel for a fluid such as liquid or gas. Examples include water pipes used for water and sewage and the like, industrial hoses used for transportation of oil, chemicals, foods, factory facilities, and the like, and preferably used for separation membrane elements. The purpose of this document is that when the water contact angle measurement is carried out on any independent 20 points on the flow channel material sample 150 mm × 150 mm, the static water contact angle is 16 points or more at 125 degrees or more. Therefore, 18 or more locations are more preferable. As an example of the water contact angle measuring device, a fully automatic contact angle meter DM-901 manufactured by Kyowa Interface Science Co., Ltd. is given as an example, and arbitrary multipoint measurement can be performed automatically. In the later part of this document, the separation membrane element used for water treatment is cited as an example of the use of the flow path material, but the present invention is not limited to this.
[2. Separation membrane element)
(2-1) Overview The form of the separation membrane element includes spiral type, hollow fiber type, plate and frame type, rotating flat membrane type, flat membrane integrated type, etc. Since the volume fraction of the flow path material with respect to the membrane element is larger than that of the elements of other forms, it is preferable as a form of the present invention. In the following, a spiral type is given as an example of the form of the separation membrane element, but it is not limited to this. As shown in FIG. 1, the separation membrane element 1 includes a water collection pipe 6 and a separation membrane main body (hereinafter simply referred to as “separation membrane”) 3 wound around the water collection pipe 6. The separation membrane element further includes members such as the supply-side flow path member 2 and an end plate.

  The separation membrane 3 forms a rectangular envelope membrane 5 with the permeate side surface facing inward. The envelope-like membrane 5 is opened only on one side so that the permeate flows into the water collecting pipe 6 and is sealed on the other three sides. The permeate is isolated from the supply water by this envelope membrane.

  The supply-side channel material 2 is disposed between the envelope-like membranes 5, that is, between the supply-side surfaces of the separation membrane 3. The supply-side channel material 2 and the plurality of envelope-like membranes 5 are wound around the water collecting pipe 6 in an overlapped state.

  The permeate-side channel material 4 is disposed so as to face the permeation side surface of the separation membrane 3, and is wound around the water collecting pipe 6 together with the separation membrane 3. Specifically, a sheet having a plurality of protrusions formed of tricot, resin, or the like can be used as the permeate-side channel material 4.

  Examples of the sheet include a nonwoven fabric, a woven fabric, and a film.

  The channel material of the present invention may be applied to at least one of the supply side channel material and the permeation side channel material.

  Supply water 7 supplied from one end in the longitudinal direction of the separation membrane element 1 is supplied to the separation membrane 3 through a flow path formed by the supply-side flow path material 2.

  Water that has permeated through the separation membrane 3 (shown as “permeated water 8” in the drawing) flows into the water collecting pipe 6 through the flow path formed by the permeate-side flow path material 4. Thus, the permeated water 8 is recovered from one end of the water collecting pipe 6.

  On the other hand, water that has not permeated the separation membrane 3 (shown as “concentrated water 9” in the figure) is recovered from the other end of the separation membrane element 1.

  A separation membrane element 1 shown in FIG. 1 is an example of a configuration of a spiral separation membrane element including a water collection pipe and a separation membrane wound around the water collection pipe, and the present invention is limited to this embodiment. is not.

(2-2) Supply-side channel material (2-2-1) Outline As shown in FIG. 2, the net that has been widely used as the supply-side channel material has the fibrous materials 21 and 22 substantially parallel to each other. It is formed by arranging. The supply-side channel material is disposed between the supply-side surfaces of two adjacent separation membranes, and a supply-side channel is formed outside the envelope-shaped membrane, that is, between the supply-side surfaces of the facing separation membranes. Is done.

(2-2-2) Constituent Component of Supply Side Channel Material The part not exposed on the surface is not particularly limited, but a resin is preferably used. For ease of melt molding, polyolefins such as ethylene vinyl acetate copolymer resin, polyethylene and polypropylene, and olefin copolymers, and polymers such as urethane resin, epoxy resin, and polyester can be selected. Can be used as a mixture.

  For the purpose of this document, the portion exposed on the surface has 16 or more locations where the static water contact angle is 125 degrees or more when the water contact angle measurement is performed for any 20 independent locations. 18 or more are more preferable. In addition, although fluorine-based polymers such as polytetrafluoroethylene and polyvinylidene fluoride have a static water contact angle of 100 degrees or more (120 degrees or less), because of their high heat resistance characteristics, melt molding is extremely difficult, Application to channel material is not realistic. On the other hand, by modifying only the surface of the flow path material as in this document, it is possible to realize a flow path material having a static water contact angle of 125 degrees or more.

(2-2-3) Form of Supply Side Channel Material The separation membrane element 1 has a projected area ratio with respect to the separation membrane 3 between 0 and less than 1 between the surfaces on the supply side of the facing separation membrane. Material (not shown). The projected area ratio of the supply-side channel material is preferably 0.03 or more and 0.50 or less, more preferably 0.10 or more and 0.40 or less, and particularly preferably 0.15 or more and 0.35 or less. . When the projected area ratio is 0.03 or more and 0.50 or less, the flow resistance can be suppressed to be relatively small. The projected area ratio refers to the projected area obtained when the separation membrane and the supply-side channel material are cut out at 5 cm × 5 cm, and the supply-side channel material is projected onto a plane parallel to the surface direction of the separation membrane. Divided value.

  Since the flow resistance of the supply-side flow path is proportional to the length of the flow path provided by the supply-side flow path material, the longer the length, the more easily the effect of improving the amount of water produced by the present invention. Specifically, the length is preferably 250 mm or more, and more preferably 500 mm or more.

  As will be described later, the height of the supply-side channel material is preferably more than 0.5 mm and not more than 2.0 mm, more preferably not less than 0.6 mm and not more than 1.0 mm, in consideration of the balance of each performance and the operation cost.

  The shape of the supply-side channel material is not particularly limited, and may have a continuous shape or a discontinuous shape. Examples of the channel material having a continuous shape include members such as a film and a net. Here, the continuous shape means that it is continuous over the entire range of the flow path material. The continuous shape may include a portion where a part of the flow path material is discontinuous to such an extent that a problem such as a decrease in the amount of water produced does not occur. “Discontinuous” refers to a shape in which the projected image on the surface of the composite separation membrane is discontinuous. That is, the discontinuous member is divided into a plurality of parts, that is, an aggregate of a plurality of members, and each member is separable from each other. In addition, the term “discontinuity” can also be said to mean that the distance between adjacent members is such that fluid can flow between the members.

(2-2-4) Effect of Supply Side Channel Material The portion exposed on the surface of the supply side channel material preferably has a static water contact angle of 125 degrees or more. Due to such supply side flow path surface characteristics exhibiting extremely high water repellency, the dynamic friction coefficient with respect to the flow path of the supply water can be reduced, and supply side flow resistance can be suppressed. A decrease in flow resistance in the supply-side flow path leads to an improvement in the flow rate of the supply water, that is, an improvement in the amount of the element water.

In addition, the low friction characteristic on the surface of the supply side flow path makes it possible to reduce the scratch damage to the separation membrane surface with which the supply side flow path material is in contact as much as possible. Furthermore, it can suppress that foulants, such as an inorganic substance and organic substance contained in supply water, adhere to a flow-path material. When the flow channel material and the separation membrane are laminated to manufacture the element and the surrounding is performed, the separation membrane is less likely to wrinkle, and the surrounding speed can be improved.
(2-3) Permeation-side channel material (2-3-1) Outline The tricot that has been widely used as the permeation-side channel material is a knitted fabric, and is composed of three-dimensionally intersecting yarns. In addition, as shown in FIG. 6 and FIG. 7, a flow path material having a sheet and a plurality of protrusions fixed to the sheet, a concavo-convex molded film, or a nonwoven fabric can be used as the permeation side flow path material. In this case, the flow resistance becomes smaller because the flow path becomes wider than when a tricot having the same thickness as the flow path material is applied. Furthermore, when the static water contact angle on the surface of the flow path is 125 degrees or more, the dynamic friction coefficient when water passes is reduced, and the flow resistance is further reduced. Examples of the sheet include a nonwoven fabric, a woven fabric, and a film. The permeate-side channel material is disposed between the permeate-side surfaces of two adjacent separation membranes, and a permeate-side channel is formed inside the envelope membrane, that is, between the permeate-side surfaces of the opposite separation membranes. Is done.

(2-3-2) Constituent Component of Permeation-side Channel Material The same as the constituent component of the supply-side channel material described in (2-2-2).

(2-3-3) Form of Permeation Side Channel Material In the spiral separation membrane element of the present invention, a permeation side channel material is disposed on the permeation side surface of the separation membrane. The permeate-side channel material has a cross-sectional area ratio of 0.4 or more and 0 in terms of reducing the flow resistance of the permeate-side channel and forming the channel stably even under pressure filtration. .9 or less. There is no limitation on the type of permeate side channel material having a cross-sectional area ratio in this range, and a weft knitted fabric in which a conventional tricot is made thick so that the channel spreads, a weft knitted fabric in which the amount of fiber is reduced, and a nonwoven fabric A concavo-convex sheet in which protrusions are arranged on such a porous sheet or a concavo-convex process of a film or a nonwoven fabric can be used.

  Here, the cross-sectional area ratio of the permeate side channel material will be described. When the permeate-side flow path material is loaded into the spiral separation membrane element, cut along the direction parallel to the longitudinal direction of the water collection pipe so as to pass through the convex portion of the permeate-side flow path material. The permeation-side channel material occupying between the center of the convex portion and the center of the adjacent convex portion with respect to the product of the distance between the center of the convex portion adjacent to the center (also referred to as pitch) and the height of the permeation-side channel material The ratio with the cross-sectional area is the cross-sectional area ratio.

  The thickness of the permeate side channel material is preferably 0.1 mm or more and 1 mm. Various methods such as an electromagnetic method, an ultrasonic method, a magnetic method, and a light transmission method are commercially available for measuring the thickness, but any method may be used as long as it is a non-contact type. Measurements are made at 10 locations at random and the average value is evaluated. By being 0.1 mm or more, it has strength as a permeate-side channel material and can be handled without causing the permeation-side channel material to be crushed or torn even when stress is applied. In addition, the number of separation membranes and flow passage materials that can be inserted into the element can be increased without impairing the surrounding property of the water collecting pipe when the thickness is 1 mm or less.

  Examples of the shape of the projection of the flow path member having a sheet and a plurality of projections fixed to the sheet include a hemispherical shape, a cone shape (including a cone shape and a pyramid shape), and a column shape (a columnar shape, a prismatic shape). Etc.) or a wall shape. That is, specific examples of the planar shape of the protrusion (the shape in the direction parallel to the surface direction of the sheet main body) include a circular shape (including an ellipse and a perfect circle) and a linear shape. Moreover, hemispherical, rectangular shape etc. are mentioned as a cross-sectional shape of the protrusion in the thickness direction of a sheet | seat. The plurality of linear or wall-like flow path members provided on one sheet may be arranged so as not to cross each other, for example, may be arranged parallel to each other.

Moreover, it is good also considering the sheet | seat which carried out the uneven | corrugated shaping | molding of the film by the embossing or the imprint process as a permeation | transmission side channel material. In this case, the irregular shaped surfaces of the sheet, by arranging so that the number density of fine protrusions having a thickness of less than 5μm to express lotus effect is 20 / mm ² or more 1000 / mm ² or less Water repellency can be imparted to the uneven sheet-like material.

  The thickness of the fine protrusion represents the height of the convex portion with reference to the deepest portion of the adjacent concave portion when attention is paid to a certain convex portion.

  The thickness of the fine protrusions is determined by cutting the concavo-convex sheet sample into CDs using an observation technique such as a transmission electron microscope (TEM), TEM tomography, or focused ion beam / scanning electron microscope (FIB / SEM). It can be measured by observation. For example, when observing with a scanning electron microscope, the sample is thinly coated with platinum, platinum-palladium, ruthenium tetroxide, preferably ruthenium tetroxide, and a high-resolution field emission scanning electron microscope (acceleration voltage of 3 to 6 kV ( Observation is performed using (UHR-FE-SEM). A Hitachi S-900 electron microscope or the like can be used as the high-resolution field emission scanning electron microscope. The observation magnification is preferably 200 to 2,000 times, and the thickness of the fine protrusions can be directly measured with a scale or the like in consideration of the observation magnification from the obtained electron micrograph. In addition, the shape of the fine protrusion of the concavo-convex sheet is not particularly limited.

The number density is obtained by measuring the number of fine protrusions having a thickness of 5 μm or less, which are present per arbitrary 1 mm ² when the sheet plane is viewed from above.

  The concavo-convex sheet is disposed as a permeate-side channel material between the permeate-side surfaces of two adjacent separation membranes, but the permeated water from the two separation membranes because the film itself has no water permeability. It is necessary to provide a through hole in the film in order to guide the liquid to the permeate side flow path. A through-hole can be obtained by performing laser processing on the concave portion in the concavo-convex from the non-concave surface of the concavo-convex imprint sheet using a Keyence 3D laser marker or the like. The position where the through-hole is provided in the concavo-convex sheet can be adjusted so that the effect of the present invention is exhibited. This is because the amount of water to be treated varies depending on the size of the separation membrane element and the operating conditions. The more water to be treated, the more through holes are required. However, it is not necessary to provide the through holes evenly over the entire surface of the uneven sheet.

  As a guide for the pattern of the through-holes, the pressure loss in the planar direction of the uneven sheet material is calculated or measured under the condition that the separation membrane element loaded with the uneven sheet material is operated, for example, calculated by the Hagen-Poiseuille equation The diameter and pitch in the planar shape of the through hole can be determined so that the pressure loss of the through hole is 10 kPa or less.

  As an example, the permeation side channel materials 41 to 43 shown in FIGS. That is, the cross section of the protrusion 401 in FIG. 3 is round at the top and rectangular at the bottom. The cross section of the protrusion 402 in FIG. 4 is trapezoidal. The cross section of the protrusion 403 in FIG. 5 is rectangular.

  The permeation-side flow path members 44 and 45 shown in FIGS. 6 and 7 each include a circular dot-shaped protrusion 404 and a wall-shaped protrusion 405. The cross section of FIGS. 3-5 may be applied to any of the forms of FIGS.

  A flow path material having a sheet and a plurality of protrusions fixed to the sheet can not only stably form a permeate-side flow path even when pressure is applied, but has a lower flow resistance than a conventional tricot. An efficient flow path can be formed.

  Moreover, it is preferable that the protrusions of the flow path member having the sheet and the plurality of protrusions fixed to the sheet are discontinuous at least in the width direction of the element. The length direction may be discontinuous or continuous, but continuous is preferable because it can suppress the drop of the composite separation membrane during pressure filtration. The definition of “discontinuity” is as described for the flow path material on the supply side.

  Since the flow resistance of the permeation side flow path is proportional to the length of the flow path provided by the permeation side flow path material, the longer the length, the easier it is to receive the water production improvement effect of the present invention. Specifically, the length is preferably 500 mm or more, and more preferably 1000 mm or more.

(2-3-4) Effect of Permeation Side Channel Material The portion exposed on the surface of the transmission side channel material has a static water contact angle of 125 degrees or more. By such permeation side channel surface characteristics exhibiting extremely high water repellency, the coefficient of dynamic friction with respect to the permeation side channel of permeate can be reduced, and permeation side flow resistance can be suppressed. A decrease in the flow resistance of the permeate side channel leads to an increase in the flow rate of the permeate, that is, an improvement in the amount of the element water. In addition, due to the low friction characteristics of the flow path surface, it is difficult for wrinkles to enter the separation membrane when stacking the flow path material and the separation membrane to produce an element, and the surrounding speed can be improved. It becomes possible.

[3. Separation membrane)
(3-1) Overview A separation membrane is a membrane that can separate components in a fluid supplied to the surface of the separation membrane and obtain a permeated fluid that has permeated the separation membrane.

  An example of such a separation membrane is shown in FIG. As shown in FIG. 8, the separation membrane 31 includes a supply-side surface 17 and a permeation-side surface 18.

  In the present invention, the “supply side surface” of the separation membrane means a surface on the side to which the water to be treated is supplied, of the two surfaces of the separation membrane. The “transmission side surface” means the opposite side surface. When the separation membrane includes the separation functional layer 15 and the base material 16 as shown in FIG. 9, generally, the surface on the separation functional layer side is the surface on the supply side and the surface on the base material side is on the transmission side. Surface.

(3-2) Separation Function Layer The thickness of the separation function layer is not limited to a specific numerical value, but is preferably 5 nm or more and 3000 nm or less in terms of separation performance and transmission performance. In particular, in the case of a reverse osmosis membrane, a forward osmosis membrane, and a nanofiltration membrane, the thickness is preferably 5 nm or more and 300 nm or less.

  The thickness of the separation functional layer can be in accordance with an ordinary separation film thickness measurement method. For example, the separation membrane is embedded with resin, and an ultrathin section is prepared by cutting the separation membrane, and the obtained section is subjected to processing such as staining. Thereafter, the thickness can be measured by observing with a transmission electron microscope. Further, when the separation functional layer has a pleat structure, measurement can be made at intervals of 50 nm in the cross-sectional length direction of the pleat structure located above the porous support layer, the number of pleats can be measured, and the average can be obtained. it can.

  The separation function layer may be a layer having both a separation function and a support function, or may have only a separation function. The “separation function layer” refers to a layer having at least a separation function.

  When the separation functional layer has both a separation function and a support function, a layer containing cellulose, polyvinylidene fluoride, polyether sulfone, or polysulfone as a main component is preferably applied as the separation functional layer.

  In this specification, “X contains Y as a main component” means that the Y content in X is 50 mass% or more, 70 mass% or more, 80 mass% or more, 90 mass% or more, or It means a case of 95% by mass or more. In addition, when there are a plurality of components corresponding to Y, the total amount of these components only needs to satisfy the above range.

  On the other hand, as the separation functional layer supported by the porous support layer, a crosslinked polymer is preferably used in terms of easy control of the pore diameter and excellent durability. In particular, a polyamide separation functional layer obtained by polycondensation of a polyfunctional amine and a polyfunctional acid halide, an organic-inorganic hybrid functional layer, and the like are preferably used in that the separation performance of components in the feed water is excellent. These separation functional layers can be formed by polycondensation of monomers on the porous support layer.

  For example, the separation functional layer can contain polyamide as a main component. Such a separation membrane is formed by interfacial polycondensation of a polyfunctional amine and a polyfunctional acid halide by a known method. For example, by applying a polyfunctional amine aqueous solution to the porous support layer, removing the excess amine aqueous solution with an air knife or the like, and then applying an organic solvent solution containing a polyfunctional acid halide, the polyamide separation functional layer Is obtained.

Further, the separation functional layer may have an organic-inorganic hybrid structure containing Si element or the like. The separation functional layer having an organic-inorganic hybrid structure can contain, for example, the following compounds (A) and (B):
(A) a silicon compound in which a reactive group and a hydrolyzable group having an ethylenically unsaturated group are directly bonded to a silicon atom, and (B) a compound other than the above compound (A) and having an ethylenically unsaturated group Compound.

Specifically, the separation functional layer may contain a condensate of the hydrolyzable group of the compound (A) and a polymer of the ethylenically unsaturated group of the compounds (A) and / or (B). That is, the separation functional layer is
A polymer formed by condensation and / or polymerization of only the compound (A),
-The polymer formed by superposing | polymerizing only a compound (B), and-At least 1 sort (s) of polymer of the copolymer of a compound (A) and a compound (B) can be contained. The polymer includes a condensate. In the copolymer of compound (A) and compound (B), compound (A) may be condensed via a hydrolyzable group.

  The hybrid structure can be formed by a known method. An example of a method for forming a hybrid structure is as follows. A reaction solution containing the compound (A) and the compound (B) is applied to the porous support layer. In order to condense the hydrolyzable group after removing the excess reaction solution, heat treatment may be performed. As a polymerization method of the ethylenically unsaturated groups of the compound (A) and the compound (B), heat treatment, electromagnetic wave irradiation, electron beam irradiation, and plasma irradiation may be performed. For the purpose of increasing the polymerization rate, a polymerization initiator, a polymerization accelerator and the like can be added during the formation of the separation functional layer.

  For any separation functional layer, the surface of the separation membrane may be hydrophilized with an alcohol-containing aqueous solution or an alkaline aqueous solution, for example, before use.

(3-3) Porous Support Layer The porous support layer is a layer that supports the separation functional layer, and can also be referred to as a porous resin layer.

  Although the material used for a porous support layer and its shape are not specifically limited, For example, you may form on a board | substrate with porous resin. As the porous support layer, polysulfone, cellulose acetate, polyvinyl chloride, epoxy resin or a mixture and laminate of them is used, and polysulfone with high chemical, mechanical and thermal stability and easy to control pore size. Is preferably used.

  The porous support layer gives mechanical strength to the separation membrane and does not have a separation performance like a separation functional layer for components having a small molecular size such as ions. The pore size and pore distribution of the porous support layer are not particularly limited. For example, the porous support layer may have uniform and fine pores, or the side on which the separation functional layer is formed. It may have a pore size distribution such that the diameter gradually increases from the surface to the other surface. In any case, the projected area equivalent circle diameter of the pores measured using an atomic force microscope or an electron microscope on the surface on the side where the separation functional layer is formed is 1 nm or more and 100 nm or less. preferable. Particularly in terms of interfacial polymerization reactivity and retention of the separation functional layer, the pores on the surface on the side where the separation functional layer is formed in the porous support layer preferably have a projected area equivalent circle diameter of 3 nm to 50 nm. .

  The thickness of the porous support layer is not particularly limited, but is preferably in the range of 20 μm or more and 500 μm or less, more preferably 30 μm or more and 300 μm or less for reasons such as giving strength to the separation membrane.

  The form of the porous support layer can be observed with a scanning electron microscope, a transmission electron microscope, or an atomic force microscope. For example, when observing with a scanning electron microscope, after peeling off the porous support layer from the substrate, it is cut by the freeze cleaving method to obtain a sample for cross-sectional observation. The sample is thinly coated with platinum, platinum-palladium or ruthenium tetrachloride, preferably ruthenium tetrachloride, and observed with a high-resolution field emission scanning electron microscope (UHR-FE-SEM) at an acceleration voltage of 3 kV to 6 kV. A Hitachi S-900 electron microscope or the like can be used as the high-resolution field emission scanning electron microscope. Based on the obtained electron micrograph, the film thickness of the porous support layer and the projected area equivalent circle diameter of the surface can be measured.

  The thickness and pore diameter of the porous support layer are average values, and the thickness of the porous support layer is measured at intervals of 20 μm in a direction orthogonal to the thickness direction in cross-sectional observation, and is an average value of 20 point measurements. . Moreover, a hole diameter is an average value of each projected area circle equivalent diameter measured about 200 holes.

  Next, a method for forming the porous support layer will be described. For example, the porous support layer has a certain thickness on a substrate, for example, a densely woven polyester cloth or non-woven fabric, which is described later, with a solution of the above polysulfone in N, N-dimethylformamide (hereinafter referred to as “DMF”). It can be manufactured by casting it into water and wet coagulating it in water.

  The porous support layer is “Office of Saleen Water Research and Development Progress Report” no. 359 (1968). In addition, in order to obtain a desired form, the polymer concentration, the temperature of the solvent, and the poor solvent can be adjusted.

  For example, a predetermined amount of polysulfone is dissolved in DMF to prepare a polysulfone resin solution having a predetermined concentration. Next, this polysulfone resin solution is applied to a substrate made of polyester cloth or nonwoven fabric to a substantially constant thickness, and after removing the surface solvent in the air for a certain period of time, the polysulfone is coagulated in the coagulation liquid. A porous support layer can be obtained.

(3-4) Substrate From the viewpoint of the strength and dimensional stability of the separation membrane, the separation membrane can have a substrate. As the base material, it is preferable to use a fibrous base material in terms of strength, unevenness forming ability and fluid permeability.

  As a base material, both a long fiber nonwoven fabric and a short fiber nonwoven fabric can be used preferably. In particular, since the long fiber nonwoven fabric has excellent film-forming properties, when the polymer solution is cast, the solution penetrates through the permeation, the porous support layer peels off, and Can prevent the separation membrane from becoming non-uniform due to fluffing of the base material and the like, and the occurrence of defects such as pinholes. In addition, since the base material is made of a long-fiber nonwoven fabric composed of thermoplastic continuous filaments, compared to a short-fiber nonwoven fabric, non-uniform film formation and film defects caused by fiber fluffing during polymer solution casting can be prevented. Can be suppressed. Furthermore, since the separation membrane is tensioned in the film-forming direction when continuously formed, it is preferable to use a long-fiber nonwoven fabric excellent in dimensional stability as a base material.

  In the long-fiber nonwoven fabric, in terms of moldability and strength, it is preferable that the fibers in the surface layer on the side opposite to the porous support layer have a longitudinal orientation than the fibers in the surface layer on the porous support layer side. According to such a structure, the high effect which prevents a film tear etc. is implement | achieved by maintaining intensity | strength.

  More specifically, the fiber orientation degree in the surface layer on the side opposite to the porous support layer of the long-fiber nonwoven fabric is preferably 0 ° or more and 25 ° or less, and the fiber orientation in the surface layer on the porous support layer side. The degree of orientation difference with respect to the degree is preferably 10 ° or more and 90 ° or less.

  The process for producing the separation membrane and the process for producing the separation membrane element include a heating step, but a phenomenon occurs in which the porous support layer or the separation functional layer contracts due to the heating. In particular, the shrinkage is remarkable in the width direction where no tension is applied in continuous film formation. Since shrinkage causes problems in dimensional stability and the like, a substrate having a small rate of thermal dimensional change is desired. In the nonwoven fabric, when the difference between the fiber orientation degree on the surface layer opposite to the porous support layer and the fiber orientation degree on the porous support layer side surface layer is 10 ° or more and 90 ° or less, the change in the width direction due to heat is suppressed. Can also be preferred.

  Here, the fiber orientation degree is an index indicating the direction of the fibers of the nonwoven fabric substrate constituting the porous support layer. Specifically, the fiber orientation degree is an average value of angles between the film forming direction when continuous film forming is performed, that is, the longitudinal direction of the nonwoven fabric base material and the longitudinal direction of the fibers constituting the nonwoven fabric base material. is there. That is, if the longitudinal direction of the fiber is parallel to the film forming direction, the fiber orientation degree is 0 °. If the longitudinal direction of the fiber is perpendicular to the film forming direction, that is, if it is parallel to the width direction of the nonwoven fabric substrate, the degree of orientation of the fiber is 90 °. Accordingly, the closer to 0 ° the fiber orientation, the longer the orientation, and the closer to 90 °, the lateral orientation.

  The degree of fiber orientation is measured as follows. First, 10 small piece samples are randomly collected from the nonwoven fabric. Next, the surface of the sample is photographed at 100 to 1000 times with a scanning electron microscope. In the photographed image, 10 fibers are selected for each sample, and the angle of the fibers in the longitudinal direction when the longitudinal direction of the nonwoven fabric is 0 ° is measured. Here, the longitudinal direction of the nonwoven fabric refers to “Machine direction” at the time of manufacturing the nonwoven fabric.

  In this way, the angle is measured for a total of 100 fibers per nonwoven fabric. For the 100 fibers thus measured, an average value is calculated from the angle in the longitudinal direction. The value obtained by rounding off the first decimal place of the obtained average value is the fiber orientation degree.

  The thickness of the substrate is selected so that the total thickness of the substrate and the porous support layer is in the range of 30 μm to 300 μm, or in the range of 50 μm to 250 μm. It is preferred that

[4. Method for manufacturing separation membrane element]
A conventional element manufacturing apparatus can be used for manufacturing the separation membrane element. In addition, as an element manufacturing method, a method described in a reference (Japanese Patent Publication No. 44-14216, Japanese Patent Publication No. 4-11928, Japanese Patent Laid-Open No. 11-226366) can be used. Details are as follows.

(4-1) Surface treatment of flow path material A low temperature plasma treatment method described in a reference (Japanese Patent Laid-Open No. Sho 63-35632) can be used to increase the water repellency of the flow path material. Details are as follows.

In a vacuum system in which the sheet-like channel material is exhausted to a certain degree of vacuum, fluorine-based gas (for example, tetrafluoroethylene (TFE, C ₂ F ₄ ), hexafluoropropene (HFP, C ₃ F ₆ ), perfluoro- One or more (2-trifluoromethyl-) pentene, perfluoro- (2-methylpent-2-ene) or its trimer) is introduced for 1 minute or more, the degree of vacuum is 0.01 to 5.0 Torr, and the discharge output is 0. .5~10W / cm ^2, the processing time performs discharge as 5-600 seconds, and that the treated structure is moved in contact with one of the discharge electrodes, the purpose of the channel member in this document can be obtained.

(4-2) Manufacture of transmission-side channel material When manufacturing a channel material having a sheet and a plurality of protrusions fixed to the sheet, for example, a step of arranging a soft material on the sheet, And a step of curing. For the arrangement of the protrusions, ultraviolet curable resin, chemical polymerization, hot melt, drying or the like is used. In particular, hot melt is preferably used. Specifically, a step of softening a material such as a resin by heat (that is, heat melting), a step of placing the softened material on a sheet, and curing the material by cooling. And a step of fixing on the sheet.

  Examples of the method for arranging the protrusions include coating, printing, spraying, and the like. Examples of the equipment used include a nozzle type hot melt applicator, a spray type hot melt applicator, a flat nozzle type hot melt applicator, a roll type coater, an extrusion type coater, a printing machine, and a sprayer. Moreover, in the case of the sheet | seat which has an unevenness | corrugation, as described in (2-3-3), a film and a nonwoven fabric can be obtained by embossing or imprinting.

  The surface water repellent property of the channel material is implemented by the method described in (4-1).

(4-3) Production of separation membrane Although the production method of the separation membrane has been described above, it can be summarized as follows.

  The resin is dissolved in a good solvent, and the resulting resin solution is cast on a substrate and immersed in pure water to combine the porous support layer and the substrate. Thereafter, as described above, a separation functional layer is formed on the porous support layer. Furthermore, chemical treatment with chlorine, acid, alkali, nitrous acid or the like is performed to improve separation performance and permeation performance as necessary, and the monomer is washed to produce a continuous sheet of separation membrane.

(4-4) Formation of flow path
When the supply-side channel material is a continuously formed member such as a net, the supply-side channel can be formed by overlapping the separation membrane and the supply-side channel material. Similarly, the permeation side flow path can be formed by overlapping the separation membrane and the permeation side flow path material.

(4-5) Formation of membrane leaf The membrane leaf may be formed by folding the separation membrane so that the surface on the supply side faces inward, or two separate separation membranes may be formed on the supply side. It may be formed by bonding so that the surfaces face each other.

  The manufacturing method of the separation membrane element preferably includes a step of sealing the inner end portion in the winding direction of the separation membrane on the surface on the supply side. In the sealing step, the two separation membranes are overlapped so that the surfaces on the supply side face each other. Further, the inner end in the winding direction of the overlapped separation membrane is sealed.

  Examples of the method of “sealing” include adhesion by an adhesive or hot melt, fusion by heating or laser, and a method of sandwiching a rubber sheet. Sealing by adhesion is particularly preferable because it is the simplest and most effective.

  At this time, a supply-side channel material formed separately from the separation membrane is disposed inside the overlapped separation membrane.

  Either the supply-side sealing or the permeation-side sealing (envelope-like membrane formation) may be performed first, or the supply-side sealing is performed while stacking separation membranes. And the sealing of the surface on the transmission side may be performed in parallel. However, in order to suppress the generation of wrinkles in the separation membrane during winding, the adhesive or hot melt at the end in the width direction is allowed to allow the adjacent separation membranes to shift in the length direction due to winding. It is preferable to complete the solidification or the like, that is, the solidification for forming an envelope-like film, after the winding is completed.

(4-6) Formation of an envelope-like membrane One separation membrane is folded and bonded so that the permeation side faces inward, or two separation membranes are laminated and pasted so that the permeation side faces inward. Thus, an envelope-like film can be formed. In the rectangular envelope film, the other three sides are sealed so that only one end in the length direction is opened. Sealing can be performed by bonding with an adhesive or hot melt, or by fusion with heat or laser.

  The adhesive used for forming the envelope film preferably has a viscosity in the range of 40P to 150P, and more preferably 50P to 120P. If the adhesive viscosity is too high, wrinkles are likely to occur when the laminated membrane leaf is wrapped around the water collection tube. Wrinkles may impair the performance of the separation membrane element. Conversely, if the adhesive viscosity is too low, the adhesive may flow out from the end of the membrane leaf and soil the device. Moreover, when an adhesive adheres to a portion other than the portion to be bonded, the performance of the separation membrane element is impaired, and the work efficiency is significantly reduced due to the processing operation of the adhesive that has flowed out.

  The amount of adhesive applied is preferably such that the width of the portion where the adhesive is applied after the membrane leaf is wrapped around the water collecting tube is 10 mm or more and 100 mm or less. As a result, the separation membrane is securely bonded, so that inflow of the feed water to the permeate side is suppressed. In addition, the effective membrane area of the separation membrane element can be secured relatively large.

  As the adhesive, a urethane-based adhesive is preferable, and in order to make the viscosity in the range of 40 P or more and 150 P or less, the isocyanate of the main agent and the polyol of the curing agent have an isocyanate / polyol mass ratio of 1/5 or more and 1 or less. Such a mixture is preferred. The viscosity of the adhesive is obtained by measuring the viscosities of a main agent, a curing agent alone, and a mixture in which a blending ratio is previously determined with a B-type viscometer (JIS K 6833).

(4-7) Separation Membrane Winding A conventional element manufacturing apparatus can be used to manufacture a separation membrane element. In addition, as an element production method, a method described in a reference document (Japanese Patent Publication No. 44-14216, Japanese Patent Publication No. 4-11928, Japanese Unexamined Patent Publication No. 11-226366) is used. it can. Details are as follows.

  When the separation membrane is wound around the water collecting pipe, the separation membrane is arranged so that the closed end of the membrane leaf, that is, the closed portion of the envelope-shaped membrane faces the water collecting pipe. By winding the separation membrane around the water collecting pipe in such an arrangement, the separation membrane is wound in a spiral shape.

  If a spacer such as a tricot or base material is wound around the water collection pipe, the adhesive applied to the water collection pipe will not flow easily when the element is wrapped, leading to suppression of leakage, and the flow path around the water collection pipe is stable. Secured. The spacer may be wound longer than the circumference of the water collecting pipe.

(4-8) Other steps The method for producing a separation membrane element may include further winding a film, a filament, and the like around the outer periphery of the wound membrane of the separation membrane formed as described above. Further steps such as edge cutting for aligning the end of the separation membrane in the longitudinal direction of the water collecting pipe, attachment of an end plate, and the like may be included.

[5. (Use of separation membrane element)
The separation membrane element may be further used as a separation membrane module by being connected in series or in parallel and housed in a pressure vessel.

  In addition, the separation membrane element and the separation membrane module described above can be combined with a pump that supplies fluid to them, a device that pretreats the fluid, and the like to form a fluid separation device. By using this separation device, for example, the supplied water can be separated into permeated water such as drinking water and concentrated water that has not permeated through the separation membrane, and water suitable for the purpose can be obtained.

  The higher the operating pressure of the fluid separator, the higher the removal rate, but the energy required for operation also increases, and considering the retention of the separation membrane element supply channel and permeation channel, the membrane module The operating pressure when passing through the water to be treated is preferably 0.5 MPa or more and 10 MPa or less. The salt removal rate decreases as the feed water temperature increases, but the membrane permeation flux decreases as the feed water temperature decreases. Further, when the pH of the feed water is in a neutral range, even if the feed water is a high salt concentration liquid such as seawater, the generation of scales such as magnesium is suppressed, and the deterioration of the separation membrane is also suppressed. .

  The fluid to be treated by the separation membrane element is not particularly limited, but when used for water treatment, the feed water is TDS (Total Dissolved Solids: total dissolved solids) of 500 mg / L or more and 100 g / L or less such as seawater, brine, drainage, etc. A liquid mixture containing a solid content). Generally, TDS refers to the total amount of dissolved solids and is expressed by “mass / volume”, but 1 L may be regarded as 1 kg and may be expressed by “mass ratio”. According to the definition, the solution filtered through a 0.45 μm filter can be calculated from the weight of the residue by evaporating at a temperature of 39.5 ° C. or higher and 40.5 ° C. or lower. Convert.

  The present invention will be described in more detail with reference to the following examples. However, the present invention is not limited to these examples.

(Static water contact angle of channel material)
The channel material was cut into a size of 150 mm × 150 mm, and a sample cut into a fully automatic contact angle meter DM-901 manufactured by Kyowa Interface Science Co., Ltd. was placed so that the measurement location was horizontal. Under an atmosphere at a temperature of 25 ° C., 1.3 μL of water droplets were dropped at 20 arbitrary locations, and the static water contact angle of the flow path material was measured at each location.
(Preparation of transmission side channel material tricot with weft knitting)
The weft knitted fabric is made of multi-filament yarn (48 filaments, 110 dtex) made by blending polyethylene terephthalate filaments (melting point: 255 ° C) with polyethylene terephthalate-based low melting point polyester filaments (melting point: 235 ° C). The weft knitting structure (gauge (number of needles between unit lengths of the knitting machine)) was knitted, heat set at 245 ° C., and then calendered to produce a permeate side channel material tricot.

In the table, the form of the permeation side channel material is indicated as A.
(Preparation of permeate-side channel material having protrusions on the nonwoven fabric)
Using an applicator loaded with a comb-shaped shim with a slit width of 0.5 mm and a pitch of 0.9 mm, the temperature of the backup roll is adjusted to 20 ° C., and when the spiral separation membrane element is used, it is perpendicular to the longitudinal direction of the water collection pipe And when it is set as an envelope-like film, a highly crystalline PP (MFR 1000 g / 10 min, linearly or discontinuously so as to be perpendicular to the longitudinal direction of the water collecting pipe from the inner end to the outer end in the winding direction. The composition pellets consisting of 60% by mass of melting point 161 ° C.) and 40% by mass of low crystalline α-olefin polymer (Idemitsu Kosan Co., Ltd .; low stereoregular polypropylene “L-MODU · S400” (trade name)) It was applied on the nonwoven fabric linearly at a temperature of 205 ° C. and a running speed of 10 m / min. The nonwoven fabric had a thickness of 0.07 mm, a weight per unit area of 35 g / m ² , and an embossed pattern (a circle with a diameter of 1 mm, a lattice with a pitch of 5 mm).

  In the table, the form of the permeation side channel material is indicated as B.

(Preparation of permeate-side channel material with a film having through holes)
Imprint processing and CO2 laser processing were applied to an unstretched polypropylene film (Toray manufactured by Toray Industries, Inc.) to obtain a permeate-side channel material having through holes. Specifically, a metal mold having grooves (width 0.5 mm, pitch 0.9 mm) arranged in parallel to each other and machined so that the number density of fine protrusions of 5 μm or less is 100 pieces / mm ^2. An unstretched polypropylene film was sandwiched, held at 140 ° C./2 minutes / 15 MPa, cooled at 40 ° C., and taken out from the mold.

  Subsequently, using a 3D-Axis CO2 laser marker MLZ9500, laser processing was performed on the concave and convex portions on the concave and convex surfaces of the concave and convex imprint sheet to obtain through holes. Note that through holes were provided in each groove with a pitch of 2 mm.

  In the table, the form of the permeation side channel material is indicated as C.

(Water production)
About the produced separation membrane element, the sodium chloride aqueous solution (TDS density | concentration of about 200 ppm) adjusted to temperature 25 degreeC and pH 7.0 was supplied with the operating pressure of 0.41 MPa, and the membrane filtration process was performed for 30 minutes, Then, sampling for 10 minutes The amount of water per day (cubic meter) was expressed as the amount of water produced (m ³ / day).

(Desalination rate (TDS removal rate))
For the feed water and the sampled permeate used in the operation for 10 minutes in the measurement of water production, the TDS concentration was determined by conductivity measurement, and the TDS removal rate was calculated from the following formula.
TDS removal rate (%) = 100 × {1− (TDS concentration in permeated water / TDS concentration in feed water)}
Example 1
On a non-woven fabric made of polyethylene terephthalate fibers (fineness: 1 dtex, thickness: about 90 μm, air permeability: 1 cc / cm ² / sec, density: 0.80 g / cm ³ ), a 17.0% by weight DMF solution of polysulfone is 180 μm. A porous support layer (thickness) composed of a fiber-reinforced polysulfone support membrane, cast at a room temperature (25 ° C.), immediately immersed in pure water for 5 minutes, and immersed in warm water at 80 ° C. for 1 minute. 130 μm) roll was produced.

  Thereafter, the surface of the porous support layer made of polysulfone was immersed in a 2.2 mass% aqueous solution of m-PDA for 2 minutes, and then slowly pulled up in the vertical direction. Furthermore, the excess aqueous solution was removed from the surface of the support film by blowing nitrogen from the air nozzle.

  Thereafter, an n-decane solution containing 0.08% by mass of trimesic acid chloride was applied so that the surface of the film was completely wetted, and then allowed to stand for 1 minute. Thereafter, excess solution was removed from the membrane by air blow, and washed with hot water at 80 ° C. for 1 minute to obtain a composite separation membrane roll.

Also, tetrafluoroethylene (TFE) was placed in a vacuum system evacuated to a certain degree of vacuum against a polypropylene net (thickness: 700 μm, pitch: 3 mm × 3 mm, fiber diameter: 0.35 mm, projected area ratio: 0.18). , C ₂ F ₄ ) was introduced for 1 minute, a plasma treatment was performed to perform discharge with a degree of vacuum of 2.0 Torr, a discharge output of 5 W / cm ² , and a treatment time of 500 seconds to obtain a supply-side channel material.

  The above plasma treatment was performed on the permeation side channel material B (thickness: 280 μm, groove width: 400 μm, ridge width: 390 μm, groove depth: 230 μm).

The composite separation membrane is folded and cut so that the effective area at the element is 0.45 m ² , the supply-side flow path material is sandwiched, and then the permeation-side flow path material is laminated to obtain a width of 254 mm. Two membrane leaves were prepared.

  The membrane leaf thus obtained was wound spirally around a water collecting tube to obtain a wound body. A film was wound around the outer periphery of the wound body and fixed with tape, and then edge cutting and end plate mounting were performed to produce a 2-inch element.

  The composite separation membrane element thus obtained is put into a pressure vessel, and the composite separation membrane element is washed by passing water for 30 minutes by a one-pass method at an operating pressure of 0.41 MPa using pure water at 25 ° C. went. Then, when 200 mg / L saline was used and operated at an operating pressure of 0.41 MPa, an operating temperature of 25.0 ° C., and a pH of 7 (recovery rate of 30%), the water production amount and the desalination rate were 0.43 m 3 / day and 96. It was 6%.

  Hereinafter, separation membrane elements were produced in the same manner as in Example 1 under conditions not specifically mentioned.

(Example 2)
A separation membrane element was produced in the same manner as in Example 1 except that the number of membrane leaves was changed to one. When the separation membrane element was put in a pressure vessel and the amount of water produced and the TDS removal rate were evaluated, the values shown in Table 1 were obtained.

(Example 3)
Separation membrane in the same manner as in Example 1 except that the permeate-side channel material was changed to the above-mentioned tricot (thickness: 260 μm, groove width: 200 μm, ridge width: 300 μm, groove depth: 105 μm). An element was produced. When the separation membrane element was put in a pressure vessel and the amount of water produced and the TDS removal rate were evaluated, the values shown in Table 1 were obtained.

Example 4
A separation membrane element is manufactured in the same manner as in Example 1 except that the supply side channel material is changed to a net not subjected to the plasma treatment and the permeation side channel material is changed to a tricot subjected to the plasma treatment. did. When the separation membrane element was put in a pressure vessel and the amount of water produced and the TDS removal rate were evaluated, the values shown in Table 1 were obtained.

(Example 5)
A separation membrane element was produced in the same manner as in Example 1 except that the supply-side channel material was changed to a net not subjected to the plasma treatment. When the separation membrane element was put in a pressure vessel and the amount of water produced and the TDS removal rate were evaluated, the values shown in Table 1 were obtained.

(Example 6)
A separation membrane element was produced in the same manner as in Example 1 except that the permeate-side channel material was changed to the tricot not subjected to the plasma treatment. When the separation membrane element was put in a pressure vessel and the amount of water produced and the TDS removal rate were evaluated, the values shown in Table 1 were obtained.

(Example 7)
Separation was carried out in the same manner as in Example 1 except that the permeation side flow path material was changed to a permeation side flow path material in which a polypropylene protrusion was fixed on a polyethylene terephthalate non-woven fabric (not subjected to the plasma treatment). A membrane element was prepared. When the separation membrane element was put in a pressure vessel and the amount of water produced and the TDS removal rate were evaluated, the values shown in Table 1 were obtained.

(Example 8)
Except for changing the permeate-side channel material to a permeate-side channel material in which the polypropylene protrusions are fixed on the non-woven fabric made of polyethylene terephthalate (the above plasma treatment has not been applied), and changing the number of membrane leaves to one. A separation membrane element was produced in the same manner as in Example 1. When the separation membrane element was put in a pressure vessel and the amount of water produced and the TDS removal rate were evaluated, the values shown in Table 1 were obtained.

Example 9
A separation membrane element was produced in the same manner as in Example 1 except that the supply-side flow path material was changed to a net not subjected to the plasma treatment, and the permeation-side flow path material was changed to an imprinted uneven sheet. . When the separation membrane element was put in a pressure vessel and the amount of water produced and the TDS removal rate were evaluated, the values shown in Table 1 were obtained.

(Example 10)
A separation membrane element was produced in the same manner as in Example 1 except that the permeation side channel material was changed to an imprinted uneven sheet. When the separation membrane element was put in a pressure vessel and the amount of water produced and the TDS removal rate were evaluated, the values shown in Table 1 were obtained.

(Example 11)
A separation membrane element was produced in the same manner as in Example 1 except that the plasma treatment time for the supply side channel material and the permeation side channel material was changed to 600 seconds. When the separation membrane element was put in a pressure vessel and the amount of water produced and the TDS removal rate were evaluated, the values shown in Table 1 were obtained.

(Comparative Example 1)
The separation membrane element was changed in the same manner as in Example 1 except that the supply side channel material was changed to a net not subjected to the plasma treatment, and the transmission side channel material was changed to a tricot not subjected to the plasma treatment. Produced. When the separation membrane element was put in a pressure vessel and the amount of water produced and the TDS removal rate were evaluated, the values shown in Table 1 were obtained.

(Comparative Example 2)
The supply-side channel material is changed to a net that has not been subjected to the above-mentioned plasma treatment, and the transmission-side channel material is replaced with a transmission-side channel material in which a polypropylene protrusion is fixed on a polyethylene terephthalate nonwoven fabric (the above-mentioned plasma treatment is applied). A separation membrane element was produced in the same manner as in Example 1 except that the change was made to (No). When the separation membrane element was put in a pressure vessel and the amount of water produced and the TDS removal rate were evaluated, the values shown in Table 1 were obtained.

(Comparative Example 3)
The separation membrane was changed in the same manner as in Example 1 except that the supply side channel material was changed to a net subjected to the plasma treatment time of 50 seconds and the permeate side channel material was changed to a tricot not subjected to the plasma treatment. An element was produced. When the separation membrane element was put in a pressure vessel and the amount of water produced and the TDS removal rate were evaluated, the values shown in Table 1 were obtained.

(Comparative Example 4)
The supply-side channel material is changed to a net subjected to the plasma treatment time of 50 seconds, and the transmission-side channel material is made of a transmission-side channel material in which a polypropylene protrusion is fixed on a polyethylene terephthalate nonwoven fabric (the plasma treatment is A separation membrane element was produced in the same manner as in Example 1 except that it was changed to (not applied). When the separation membrane element was put in a pressure vessel and the amount of water produced and the TDS removal rate were evaluated, the values shown in Table 1 were obtained.

(Comparative Example 5)
Separation membrane element in the same manner as in Example 1 except that the supply-side channel material is changed to a net not subjected to the plasma treatment, and the permeate-side channel material is changed to a tricot subjected to the plasma treatment for 50 seconds. Was made. When the separation membrane element was put in a pressure vessel and the amount of water produced and the TDS removal rate were evaluated, the values shown in Table 1 were obtained.

(Comparative Example 6)
The supply side channel material is changed to a net not subjected to the plasma treatment, and the permeation side channel material is subjected to the plasma treatment for 50 seconds, and the polypropylene protrusion is fixed on the polyethylene terephthalate nonwoven fabric. A separation membrane element was produced in the same manner as in Example 1 except that the road material was changed. When the separation membrane element was put in a pressure vessel and the amount of water produced and the TDS removal rate were evaluated, the values shown in Table 1 were obtained.

(Comparative Example 7)
The supply-side channel material is changed to a net that has not been subjected to the above-mentioned plasma treatment, and the transmission-side channel material is replaced with a transmission-side channel material in which a polypropylene protrusion is fixed on a polyethylene terephthalate nonwoven fabric (the above-mentioned plasma treatment is applied). The separation membrane element was produced in the same manner as in Example 1 except that the number of membrane leaves was changed to 1. When the separation membrane element was put in a pressure vessel and the amount of water produced and the TDS removal rate were evaluated, the values shown in Table 1 were obtained.

  The membrane element of the present invention can be suitably used particularly for brine or seawater desalination.

DESCRIPTION OF SYMBOLS 1 Separation membrane element 2 Supply side flow path material 21, 22 Fibrous materials 3, 31, 32 Separation membrane 4, 41-45 Permeation side flow path material 40 Sheets 401-405 used for permeation side flow path material Permeation side flow path Protrusion 5 provided on the material Envelope-shaped membrane 6 Water collecting pipe 7 Supply water (treated water)
8 Permeated water 9 Concentrated water 11, 15 Separation function layer 12 Porous support layers 13, 16 Base material 17 Supply side surface 18 Permeation side surface

Claims (10)

  A channel material with a surface with a static water contact angle of 125 degrees or more. The surface with a static water contact angle of 125 degrees or more occupies 80% or more of the total surface area.
The channel material according to claim 1 or 2. Fluorine is present as a constituent element on the surface,
The channel material according to claim 1.   The flow path material according to claim 1, which is used for a separation membrane element.   The flow path material according to claim 4, wherein the separation membrane element is a spiral type. A separation membrane element comprising a water collecting pipe, a separation membrane body having a supply side surface and a permeation side surface, a supply side flow channel material, and a permeation side flow channel material,
A separation membrane element using the channel material according to any one of claims 1 to 3 in at least one of the supply side channel material and the permeation side channel material. A permeation-side flow path member provided to face the permeation-side surface of the separation membrane body and having a sheet and a plurality of protrusions fixed on the sheet;
The separation membrane element according to claim 6. The protrusion is continuous in a direction perpendicular to the longitudinal direction of the water collecting pipe,
The separation membrane element according to claim 6 or 7. The permeate-side flow path material includes an open area by a through-hole in the thickness direction and other non-open areas, and the non-open area includes a plurality of fine protrusions.
The separation membrane element according to claim 6. The fine protrusions have a thickness of 5 μm or less and a number density of 20 pieces / mm ² or more and 1000 pieces / mm ² or less.
The separation membrane element according to claim 9.

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