JP2014193460A - Separation membrane and separation membrane element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a separation membrane element which is effective to: the performance improvement of separation and removal when operating the separation membrane element under pressure; the performance improvement of the separation membrane element such as the increase of a permeated water amount per unit time and the like; and stable performance.SOLUTION: A separation membrane comprises: a separation membrane body having a supply side surface and a permeation side surface; a plurality of high flow path materials being fixed on the supply side surface of the separation membrane body and having a height H1 of 0.45 mm or more and 2 mm or less; and a low flow path material being fixed on the supply side surface of the separation membrane body, having a height H2 of 0.03 mm or more and 0.4 mm or less and being placed between the high flow path materials.

Description

  The present invention relates to a separation membrane element used for separating components contained in a fluid such as liquid and gas.

  There are various methods for separating components contained in fluid such as liquid and gas. For example, taking a technique for removing ionic substances contained in seawater, brine, and the like as an example, in recent years, the use of a separation method using a separation membrane element is expanding as a process for saving energy and resources. Separation membranes used in separation methods using separation membrane elements include microfiltration membranes, ultrafiltration membranes, nanofiltration membranes, reverse osmosis membranes, and forward osmosis membranes in terms of their pore size and separation function. Membranes are used to obtain drinking water from, for example, seawater, brine, and water containing harmful substances, and are used for the production of industrial ultrapure water, wastewater treatment, recovery of valuable materials, etc. Depending on the separation performance.

  The separation membrane element is common in that raw fluid is supplied to one side of the separation membrane and permeate is obtained from the other side. The separation membrane element is configured to bundle a large number of separation membrane elements of various shapes to increase the membrane area and to obtain a large amount of permeated water per unit element. Various elements such as molds, hollow fiber types, plate-and-frame types, rotating flat membrane types, and flat membrane integrated types are manufactured.

  For example, taking a fluid separation membrane element used for reverse osmosis filtration as an example, the separation membrane element member is a supply-side flow path material that supplies the raw fluid to the separation membrane surface, and a separation that separates components contained in the raw fluid A spiral separation membrane element in which a member made of a permeate-side flow path material for guiding a permeate-side fluid that has permeated the separation membrane and separated from the supply-side fluid to the central tube is wound around the central tube. It is widely used in that it applies pressure to the fluid and extracts a large amount of permeated water.

  For example, as a member of a spiral-type reverse osmosis separation membrane element, a polymer net is mainly used for forming a supply-side fluid flow path in the supply-side flow path material, and a separation membrane such as polyamide is used. Separation functional layer made of cross-linked polymer, porous resin layer made of polymer such as polysulfone, and separation membrane in which non-woven fabric made of polymer such as polyethylene terephthalate is laminated from the supply side to the permeate side are used. In the 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 membrane from dropping and forming a permeate side channel.

  In recent years, the need for higher performance of membrane elements has been demanded due to the increase in water production cost of separation membrane elements. In order to increase the separation performance of the separation membrane element and the amount of permeated water per unit time, it has been proposed to improve the performance of each flow path member and separation membrane element member. For example, in Patent Document 1, a spiral separation membrane having a spiral membrane element in which a flat membrane provided with a plurality of dots in a predetermined direction is laminated on the surface or both surfaces of the flat membrane and spirally wound around the outer periphery of a water collecting pipe A module is disclosed. In Patent Document 2, it is described that regular irregularities are provided on the surface or both surfaces of a flat membrane, and the irregularities turbulent the flow of raw water.

JP 2012-40487 Special table 2012-518538

  However, the separation membrane element described above cannot be said to have sufficiently high performance stability, and the separation performance may deteriorate during use.

  Accordingly, an object of the present invention is to provide a separation membrane and a separation membrane element that can stabilize the separation and removal performance when the separation membrane element is operated under a particularly high pressure.

  In order to achieve the above object, the present invention has the following configuration. That is, the separation membrane of the present invention is fixed to a separation membrane body having a supply side surface and a permeation side surface, and a supply side surface of the separation membrane body, and has a height of 0.45 mm to 2 mm. A plurality of high flow path materials and a low flow path material that is fixed to the supply side surface of the separation membrane main body and has a height of 0.03 mm to 0.4 mm and is disposed between the high flow path materials And comprising.

  The separation membrane is applicable to a separation membrane element including a water collection pipe and the separation membrane wound around the water collection pipe.

  According to the configuration of the present invention, the channel material having a large height and the channel material having a small height are provided on the surface on the supply side of one separation membrane. A turbulent flow of raw water in the direction of the membrane surface occurs due to the channel material having a large height, and a turbulent flow of raw water in a direction perpendicular to the membrane surface occurs due to the channel material having a small height. As a result, the occurrence of concentration polarization is suppressed, so that stable separation performance can be maintained.

It is the perspective view which expanded a part of separation membrane element of this invention. It is an expansion | deployment perspective view of the separation membrane element of this invention. It is a top view which shows a lattice-like granular material pattern typically. It is a top view which shows a staggered granular material pattern typically. It is a top view which shows an example of a supply side channel material. It is a top view which shows the other example of the supply side channel material. It is a top view which shows the other example of the supply side channel material. It is a top view which shows the other example of the supply side channel material. It is a top view which shows the other example of the supply side channel material. It is a top view which shows the other example of the supply side channel material. It is a top view which shows the other example of the supply side channel material. It is a top view which shows the other example of the supply side channel material. It is a top view which shows the other example of the supply side channel material. It is a top view which shows the other example of the supply side channel material. It is a top view which shows the other example of the supply side channel material. It is a top view which shows the other example of the supply side channel material. It is a top view which shows the other example of the supply side channel material. It is a top view which shows the other example of the supply side channel material. FIG. 3 is a plan view showing a supply-side channel material arrangement in Example 1. FIG. 10 is a plan view showing a supply-side channel material arrangement in Example 11. It is a cross-sectional view showing an example of a separation membrane.

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

[1. Separation membrane element)
Next, an example of the form of the spiral separation membrane element will be described with reference to FIG.

  As shown in FIG. 1, the separation membrane element 1 includes a water collection pipe 2, a separation membrane 3, a supply-side channel material 4, a permeation-side channel material 5, an upstream end plate 7, and a downstream end plate 8. The separation membrane element 1 can separate the raw water 101 into the permeated water 102 and the concentrated water 103.

  The water collecting pipe 2 is a cylindrical member that is long in one direction (the x-axis direction in the figure). A plurality of holes are provided on the side surface of the water collecting pipe 2.

  The separation membrane 3 may be a membrane having the desired separation performance as described above. The separation membrane 3 has a supply-side surface 31 in contact with the raw water 101 and a permeation-side surface 32 in contact with the permeated water 102.

  The supply-side channel material is provided on the supply-side surface 31 of the separation membrane 3. The supply-side channel material includes a high channel material 41A, a low channel material 41B, and an end channel material 42, as will be described later.

  As the permeation side channel material 5, a conventional channel material can be applied, and for example, a knitted fabric such as tricot is used. The permeate-side channel material 5 is disposed between two opposing permeate-side surfaces 32 in an envelope-like film 6 described later. However, the permeate-side channel material 5 can be changed to another member that can form a permeate-side channel between the separation membranes 3. Moreover, the permeation | transmission side channel material 5 can also be abbreviate | omitted by using the separation membrane in which the unevenness | corrugation was formed as the separation membrane 3. FIG. Details of the permeation side channel material and other examples will be described later.

  The envelope-like membrane 6 is formed by two separation membranes 3 that are overlapped so that the permeation side surface 32 is on the inside, or by one folded separation membrane 3. The planar shape of the envelope membrane 6 is a rectangle, and the separation membrane 3 is closed on three sides, and one side is open. The envelope-like membrane 6 is arranged so that the opening thereof faces the water collecting pipe 2, and is further wound around the water collecting pipe 2. In the separation membrane element 1, a plurality of envelope membranes 6 are wound so as to overlap each other. The outer surface of the envelope-shaped film 6 is a supply-side surface 31, and the adjacent envelope-shaped films 6 are arranged so that the supply-side surfaces 31 face each other. That is, a supply-side flow path is formed between adjacent envelope-shaped films 6, and a permeate-side flow path is formed inside the envelope-shaped film 6.

  The upstream end plate 7 and the downstream end plate 8 are attached to the upstream end 21 and the downstream end 22 of the wound body, respectively.

  The separation membrane element 1 can include members other than those described above. For example, the periphery of the wound body of the separation membrane may be covered with another member such as a film.

  The raw water 101 is supplied to the surface 31 on the supply side of the separation membrane 3 via the upstream end plate 7. The permeated water 102 that has permeated the separation membrane 3 flows into the water collecting pipe 2 through a flow path formed in the envelope-shaped membrane 6 by the permeate-side flow path material 5. The permeated water that has flowed through the water collecting pipe 2 is discharged to the outside of the separation membrane element 1 through the end plate 8. Further, the concentrated water 103 is discharged from the end plate 8 to the outside through the space 31 on the supply side. Thus, the raw water 101 is separated into the permeated water 102 and the concentrated water 103.

  Details of each member will be described below.

[2. Separation membrane)
(2-1) 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. Hereinafter, for convenience of explanation, a complex of the separation membrane main body 30 and the flow path material fixed to the supply side surface of the separation membrane main body 30 is referred to as a separation membrane 3.

  In this document, the “supply side surface” of the separation membrane body 30 means a surface on the side to which the raw fluid is supplied, of the two surfaces of the separation membrane body. The “transmission side surface” means the opposite side surface. When the separation membrane main body includes a base material and a separation functional layer, 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 the surface on the transmission side.

  The x-axis, y-axis, and z-axis direction axes are shown in the figure. The x-axis may be referred to as the width direction and the y-axis may be referred to as the length direction. As shown in FIG. 1 and the like, the separation membrane main body 30 is rectangular, and the width direction and the length direction are parallel to the outer edge of the separation membrane main body 30. The height direction is perpendicular to the width direction and the length direction.

  The separation membrane 3 is an element, and the separation membrane 3 is wound around the water collecting pipe 2 and arranged so that the width direction thereof is along the longitudinal direction of the water collecting pipe 2. As a result, the separation membrane 3 is arranged such that its length direction is along the winding direction. The “inner side in the winding direction” and “outer side in the winding direction” can also be referred to as the side closer to the water collecting pipe and the far side in the separation membrane, respectively.

(2-2) Separation membrane body <Overview>
As the separation membrane body 30, a membrane having separation performance according to the method of use, purpose, and the like is used. The separation membrane main body 30 may be formed of a single layer or a composite membrane including a separation functional layer and a base material. In the composite membrane, a porous support layer may be formed between the separation functional layer and the substrate.

<Separation function layer>
The thickness of the separation functional 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 a reverse osmosis membrane, a forward osmosis membrane, and a nanofiltration membrane, the thickness of the separation functional layer is preferably 5 nm or more and 300 nm or less.

  The thickness of the separation functional layer can be based on the conventional method for measuring the thickness of the separation membrane. 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 document, “X contains Y as a main component” means that the Y content in X is 50% by mass, 70% by mass, 80% by mass, 90% by mass, or 95% by mass. It means that it is more than%. 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 porous support layer separating functional 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 raw fluid 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 film 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. Examples of the separation functional layer having an organic-inorganic hybrid structure include 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 compound (A) and having an ethylenically unsaturated group Compounds can be included. 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 the compound (A) and the compound (B), the compound (A) may be condensed through 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 membrane may be hydrophilized with an alcohol-containing aqueous solution or an alkaline aqueous solution, for example, before use.

<Porous support layer>
The porous support layer is a layer that supports the separation functional layer, and is also 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 separation performance like a separation membrane 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. In particular, from the viewpoint of interfacial polymerization reactivity and retention of the separation functional layer, the pores on the surface of the porous support layer on which the separation functional layer is formed preferably have a projected area circle equivalent diameter of 3 nm to 50 nm.

  The thickness of the porous support layer is not particularly limited, but for reasons such as giving strength to the separation membrane, it is preferably in the range of 0.02 mm to 0.5 mm, more preferably 0.03 mm to 0.3 mm. It is as follows.

  The form of the porous support layer can be observed with a scanning electron microscope, a transmission electron microscope, or an atomic 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 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 0.02 mm in a direction perpendicular to the thickness direction by cross-sectional observation, and is an average value of 20 points. 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 is prepared by pouring an N, N-dimethylformamide (hereinafter referred to as DMF) solution of the above polysulfone into a constant thickness on a substrate to be described later, for example, a densely woven polyester cloth or non-woven cloth. It can be produced by molding 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. Can be obtained.

<Base material>
From the viewpoint of the strength and dimensional stability of the separation membrane main body 30, the separation membrane main body 30 may have a base material. 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 suppress the film from becoming non-uniform due to fluffing of the substrate and the like, and the occurrence of defects such as pinholes. In addition, since the base material is made of a long-fiber non-woven fabric composed of thermoplastic continuous filaments, compared to short-fiber non-woven fabrics, it suppresses the occurrence of non-uniformity and film defects caused by fiber fluffing during casting of a polymer solution. be able to. 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, it is preferable that the fibers in the surface layer on the side opposite to the porous support layer have a vertical orientation with respect to the fibers in the surface layer on the porous support layer side in terms of moldability and strength. According to such a structure, not only a high effect of preventing membrane breakage by maintaining strength is realized, but also a laminate comprising a porous support layer and a substrate when imparting irregularities to the separation membrane The moldability is improved, and the uneven shape on the surface of the separation membrane is stabilized, which is preferable.

  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 separation membrane manufacturing process and the element manufacturing process include a heating process, 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 formation is performed, that is, the longitudinal direction of the nonwoven fabric base material, and the fibers constituting the nonwoven fabric base material. 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 fiber orientation degree is closer to 0 °, and the fiber orientation is closer to 90 °.

  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 samples are selected for each sample, and the angle when the longitudinal direction (vertical direction, film forming direction) of the nonwoven fabric is set to 0 ° is measured. That is, the angle is measured for a total of 100 fibers per nonwoven fabric. An average value is calculated from the angles of 100 fibers thus measured. The value obtained by rounding off the first decimal place of the obtained average value is the fiber orientation degree.

  The thickness of the base material is preferably set to an extent that is in the range of 0.03 mm to 0.3 mm, or in the range of 0.05 mm to 0.25 mm.

(2-3) Supply-side channel material The channel material provided on the supply-side surface of the separation membrane will be described below. As shown in FIG. 1, the separation membrane 3 is overlapped, so that a flow path is formed between the separation membranes by the supply-side flow path material.

<High channel material 41A>
A plurality of high flow path materials 41A are provided for one separation membrane. The high flow path material 41A mainly functions as a spacer between the separation membranes to form a supply-side flow path. Further, the high flow path material 41A plays a role of disturbing the flow of raw water in the horizontal direction (film surface direction). The high flow path material 41A may be formed on only one of the faces on the supply side facing each other, or may be formed on both.

(height)
The height H1 (see FIG. 21) of the high flow path material 41A is determined in consideration of the flow resistance and the number of membrane leaves filled in the separation membrane element. The larger the height, the smaller the flow resistance in the flow path, and the separation characteristics and the water permeation performance can be improved. In particular, the height of the high flow path member 41A is preferably 0.45 mm or more or 0.5 mm or more. In addition, the smaller the height, the greater the number of separation membrane leaves per element, so that the water production capacity of the element is increased, and a large amount of water production can be obtained while keeping operating costs low. . In particular, the height of the high flow path material is preferably 2 mm or less or 1 mm or less.

  A separation membrane leaf (sometimes simply referred to as a leaf) is a set of two separation membranes cut to a length suitable for incorporation into an element. The separation membrane leaf is formed by folding or bonding the separation membrane.

  The height of the supply-side supply-side channel material can be measured using a commercially available shape measurement system or the like. For example, the thickness can be measured from a cross section with a laser microscope, or measured with a high-precision shape measuring system KS-1100 manufactured by Keyence. The measurement can be performed at an arbitrary location where the supply-side supply-side channel material is present, and a value obtained by summing up the height values can be divided by the total number of measurement locations.

(shape)
The shape of the high flow path material 41A in the entire separation membrane is not particularly limited, such as a discontinuous shape such as a dot or a continuous shape such as a net shape, but a discontinuous shape is preferable in order to reduce the flow resistance.

  In the case of a discontinuous shape, the shape of the individual high flow path material 41A is not particularly limited, so that the flow resistance of the flow path is reduced, and the flow path when supplying and permeating the original fluid to the separation membrane is stabilized. Can be changed. For example, the planar shape of the high channel material 41A (the shape observed from the upper surface of the separation membrane) may be an ellipse, a circle, an ellipse, a trapezoid, a triangle, a rectangle, a square, a parallelogram, a rhombus, and an indefinite shape. Good. The three-dimensional shape of the high flow path material 41A includes a shape in which the width becomes narrower as it approaches the surface of the separation membrane body 30 in the height direction, a shape in which the width of the supply-side flow path material is constant, and the separation membrane body 30 Any shape that expands as it approaches the surface of the film can be selected. However, as the width increases, the flow velocity on the film surface increases, and this is particularly preferable because concentration polarization is suppressed by increasing the turbulence intensity. A shape between 70 μm from the surface of the separation membrane main body 30 is particularly important, and in this range, the above-mentioned shape is preferable.

(Diameter, aspect ratio and pitch)
For the same reason as the height, the length (the maximum value of the size in the MD direction) and the width (the maximum value of the size in the MD) and the width (the maximum value in the CD direction) of the high flow path member 41A are preferably 0.1 mm or more and 30 mm or less. More preferably, it is 0.2 mm or more and 10 mm or less. The aspect ratio of the high flow path material 41A when observed from the upper part of the film surface is 1 or more and 15 or less. The aspect ratio is a value obtained by dividing the width of the high flow path material 41A by the length. The length direction refers to Machine Direction (MD), and the width direction refers to Cross Direction (CD).

  Further, the pitch between the high flow path materials 41A may be appropriately designed between 1/10 and 50 times the resin diameter. The pitch is a horizontal distance between the highest point in a certain supply-side channel material and the highest point of another supply-side channel material adjacent to this supply-side channel material.

(pattern)
The pattern of the high flow path material 41A is not particularly limited as long as it secures the flow path and disturbs the flow of the raw water in the horizontal direction, and can be patterned in a so-called lattice shape or zigzag pattern according to the purpose, or A combination may be used, but a staggered shape is preferable because the raw fluid can be uniformly supplied to the separation membrane. If the raw fluid can be uniformly supplied to the separation membrane, the turbulent flow effect (stirring effect) on the membrane surface becomes large, and the separation performance is hardly lowered due to concentration polarization or the like. When the separation membrane of the present invention is wrapped around the element, a leaf is produced so that the supply surfaces of the separation membrane are paired by folding or bonding. At this time, the supply-side channel material may be disposed only on one surface, or a desired arrangement may be made with the supply-side channel material fixed to the two separation membranes.

  The lattice shape is formed at a constant pitch in at least two directions substantially perpendicular to each other so that the nearest four dots 411, 412, 413, and 414 form a substantially square shape as in the separation membrane 3 of FIG. A staggered pattern means a three-dot pattern 415, 416, and 417 formed at a constant pitch in at least three directions so as to form the apex of a substantially equilateral triangle as in the separation membrane 3 of FIG. Means embodiment.

  Specifically, an angle between straight lines connecting the high flow path material 41A and the two high flow path materials 41A adjacent to the high flow path material in the flow direction of the raw water (α in FIGS. 5 and 6). Is preferably 20 ° or more and 160 ° or less, and more preferably 35 ° or more and 80 ° or less.

  When the pitch of the high flow path material 41A is equal in the row direction and the column direction, the angle α is 45 ° as shown in FIG. 5 if it is a lattice shape, and this angle α if it is staggered as shown in FIG. Is 90 °.

  Note that “two adjacent high flow channel materials” with respect to a certain high flow channel material are separated from one reference high flow channel material 41A in the flow direction of the raw water and serve as a reference high flow material. Two high flow path materials having the smallest distance from the road material are selected. At this time, both of the two high flow path materials are selected from the upstream side of the reference high flow path material or selected from the downstream side.

  For example, in FIG. 5, when two high flow path materials close to the reference high flow path material 413 are selected, the middle of the high flow path material on the downstream side of the reference high flow path material is selected. Therefore, the closest one high flow path material 411 and the second closest high flow path material 412 are selected. In the zigzag example of FIG. 6, the two high flow path members 415 and 416 that are the closest and the same distance apart from the high flow path material on the downstream side of the reference high flow path material 417 are the same. Selected. That is, the distance between the reference high flow path material and the two high flow path materials 41A adjacent thereto may be equal if they are different.

<Low channel material 41B>
(height)
The height H2 (FIG. 21) of the low flow path material 41B is preferably smaller than the height H1 of the high flow path material 41A. By providing such a low flow path material 41B, a gap through which raw water flows can be secured between the high flow path materials 41A. That is, the flow resistance can be suppressed by ensuring the height (that is, the depth) of the supply-side flow path. As a result, a high amount of fresh water can be obtained. When such a low flow path material 41B is provided, when the raw water exceeds the low flow path material 41B, the flow direction of the raw water varies in the height direction (direction perpendicular to the membrane surface).

  Thus, in the flow of raw water, not only the disturbance in the film surface direction due to the high flow path material 41A but also the disturbance in the height direction due to the low flow path material 41B occurs. Thus, concentration polarization is effectively suppressed.

  The height H2 of the low flow path material 41B is preferably 0.03 mm or more because an effect of disturbing the flow of raw water in the height direction is obtained, and the height H2 is more preferably 0.1 mm or more.

  In addition, it is preferable that the height H2 of the low flow path material is 0.4 mm or less because a flow path between the high flow path materials 41A can be secured and an increase in flow resistance can be suppressed. The height H2 is more preferably 0.3 mm or less.

In particular, in order to generate turbulent flow in the film surface direction and height direction while suppressing flow resistance, the ratio of H1 and H2 is:
0.1 ≦ (H2 / H1) ≦ 0.9
Preferably 0.1 ≦ (H2 / H1) ≦ 0.4.
It is preferable to satisfy.

  The low flow path material 41B may be provided on both surfaces on the supply side of the separation membrane facing each other, or may be provided only on one side.

(shape)
The shape of the low flow path material 41B in the entire separation membrane is not particularly limited, such as a discontinuous shape such as dots, a continuous shape such as a net shape, or a shape continuous with the high flow path material 41A.

  The shape of the low flow path material 41B in the height direction is such that the width becomes narrower as it approaches the surface of the separation membrane body 30, the shape where the width of the supply side flow path material is constant, and the closer to the surface of the separation membrane body 30 Any of the wide shapes can be selected. In particular, a shape whose width increases as it approaches the surface of the separation membrane main body 30 is particularly preferable because the flow velocity on the membrane surface increases, and concentration polarization is suppressed by increasing the turbulent strength. In particular, the shape between 70 μm from the surface of the separation membrane main body 30 is important, and the above-mentioned shape is preferable within this range.

  In the case of a discontinuous shape, the shape of each high flow path material 41A is not particularly limited, and can be changed so as to reduce the flow resistance of the flow path and disturb the flow of raw water in the height direction. A shape similar to that of the material 41A can be applied.

  The low flow path material 41B may be continuous with the high flow path material 41A. In this case, it may be continuous in any direction as shown in FIG. 7, or may be continuous in one direction as shown in FIGS. Particularly in these forms, the low flow path material is continuously formed so as to connect the high flow path materials.

(Dimensions and aspect ratio)
For the same reason as the height, the length of the low flow path material 41B (length direction, that is, the maximum value in the MD) is preferably 0.1 mm or more and 30 mm or less, and more preferably 0.2 mm or more and 10 mm or less. The width of the low flow path material 41B (the maximum value in the width direction, that is, the CD size) is not particularly limited. The aspect ratio when observed from the upper part of the film surface when the low channel material 41B is not continuous with the high channel material 41A is preferably 1 or more and 15 or less. The aspect ratio is a value obtained by dividing the width of the low flow path material 41B by the length.

(pattern)
The pattern of the low flow path material 41B is not particularly limited as long as it disturbs the flow in the height direction of the raw water. For example, it may be interposed between a plurality of high flow path materials 41A as shown in FIG. A plurality may be interposed as shown in FIG. By disturbing not only the flow direction of raw water but also the flow in the height direction, concentration polarization can be efficiently suppressed, and the water-making property and solute removal performance of the separation membrane element can be enhanced.

  When it is continuous with the high flow path material 41A, for example, it is continuous in the length direction of the high flow path material 41A arranged in a staggered manner, and has a larger diameter than the high flow path material 41A as shown in FIG. In this case, an equivalent pattern may be used as shown in FIG.

<End channel material>
On the supply side surface of the separation membrane 3, band-shaped regions 33 and 34 may be provided at the end portions. 1 and FIG. 2 is present at the end of the separation membrane 3 to facilitate the inflow of raw water of the separation membrane element, and can be stably operated even if pressure filtration is continued for a long time. .

  The edges of the strip regions 33 and 34 do not need to coincide with the edges of the separation membrane 3, and the strip regions may be separated from the edges of the separation membrane. However, the distance between the strip region 33 and the upstream edge of the separation membrane, and the distance between the strip region 34 and the downstream edge of the separation membrane are, for example, 5% or less of the width W0 of the separation membrane 3 in the x-axis direction. Or 1% or less. As described above, the supply-side channel material 4 is provided in the vicinity of the edge of the separation membrane in the x-axis direction, particularly in the vicinity of the upstream edge, so that the raw water 101 is efficiently supplied to the supply-side surface 31. Supplied.

  In addition, the “end portion” where the band-like region is provided specifically refers to a region within 20% of the width W0 of the separation membrane 3 in the x-axis direction from the edge in the x-axis direction of the separation membrane 3. That is, the end channel material 42 is disposed within a range of 20% of the width W0 of the separation membrane 3 in the x-axis direction from the edge of the separation membrane 3 in the x-axis direction.

  In addition, since the width W1 of the belt-like region 33 and the width W2 of the belt-like region 34 are each 1% or more of the width W0, the raw fluid is stably supplied to the supply-side surface 31.

  Furthermore, the sum of the widths W1 and W2 of the belt-like regions may be set to about 10% to 60% of the width W0. When the total ratio of the widths W1 and W2 to the width W0 is 60% or less, the flow resistance and the pressure loss are reduced. Moreover, when this ratio is 10% or more, the occurrence of concentration polarization can be suppressed by the turbulent flow effect. Further, the widths W1 and W2 may each be 10% or more of W0.

  As an example of such a form, in this embodiment, the shape and magnitude | size of the strip | belt-shaped area | regions 33 and 34 are the same. That is, the widths W1 and W2 in FIG. 17 are the same. The widths W1 and W2 are constant.

  As described above, the end flow path member 42 is disposed at the end of the supply-side surface 31, so that the flow path of the raw water 101 is secured between the two supply-side surfaces 31 facing each other. In the present embodiment, two strip regions 33 and 34 are provided on one supply-side surface 31, but the present invention is not limited to this form, and the strip region is in the x-axis direction. It may be provided only at one end, that is, one end on the upstream side or the downstream side.

  As the configuration of the material and shape of the end channel material 42, the same configuration as the above-described high supply side channel material 41 and low channel material 41B can be applied. However, in one separation membrane, the applied shape and material may be the same or different from each other for the end channel material 42, the high channel material 41A, and the low channel material 41B. Also good. Moreover, although the dimension of the edge part flow-path material 42 does not need to satisfy | fill the ratio of height / width mentioned above about the high flow-path material 41A or the low flow-path material 41B, it is preferable to satisfy | fill.

  Each end channel material 42 is linear, and the longitudinal direction thereof is arranged obliquely with respect to the longitudinal direction (x-axis direction) of the water collecting pipe 2. In particular, in FIG. 2, the end channel materials 42 are arranged in parallel to each other. That is, in FIG. 17, the end channel material 42 has a stripe shape.

  “Oblique” means deviating from a parallel arrangement and a vertical arrangement. That is, the angle θ between the longitudinal direction of the end channel material 42 and the x-axis direction is greater than 0 ° and less than 90 °. Note that the angle θ indicates an absolute value of an acute angle. That is, two resin bodies that are line-symmetric with respect to the x-axis exhibit the same angle θ.

  When the angle θ is less than 90 °, the flow of the raw fluid 101 is disturbed, so that concentration polarization hardly occurs and good separation performance is realized. When the angle θ is larger than 0 °, the effect of suppressing concentration polarization is further increased. Further, when the angle θ is 60 ° or less, the flow resistance of the raw fluid is relatively low, and a high suppression effect on the concentration polarization can be obtained. Furthermore, in order to produce a turbulent flow effect while reducing the flow resistance, it is more preferably greater than 15 ° and 45 ° or less.

  The end channel material 42 is arranged so as to intersect with each other on both surfaces of the supply side facing each other, thereby ensuring a larger channel height. Specifically, as described above, the end channel material 42 arranged in an oblique stripe form forms a cross structure as shown in FIG. 18 when folded or bonded to form a separation membrane leaf. The stability of the flow path can be improved.

  In the striped arrangement, the upstream channel material and the downstream channel material may be parallel or non-parallel. For example, in the striped arrangement, the upstream-side channel material and the downstream-side channel material may be line symmetric or asymmetric with respect to the y-axis.

  The above-described high flow path material and low flow path material are disposed between the strip-shaped end portions 33 and 34 described above.

<Formation method of channel material>
The method of arranging the high flow path material, the low flow path material, and the end flow path material on the surface on the supply side of the separation membrane is not particularly limited, but a nozzle type hot melt applicator, a spray type hot melt applicator, a flat nozzle type Such methods as hot melt applicator, roll type coater, gravure method, extrusion type coater, printing and spraying are used.

<Material>
Although it does not specifically limit as a component which comprises a flow-path material, From the point of chemical resistance, polyolefin, such as ethylene vinyl acetate copolymer resin, polyethylene, and polypropylene, and copolymer polyolefin are preferable, such as urethane resin and epoxy resin. A polymer can also be selected. However, since a thermoplastic resin is easy to mold, the shape of the channel material can be made uniform.

[3. Permeate side channel material)
The permeate-side channel material 5 only needs to be configured so that permeated water can reach the perforated water collecting pipe, and the shape, size, material, and the like are not limited to a specific configuration.

  By having a composition different from that of the separation membrane, the permeation-side channel material 5 can exhibit higher resistance to pressure than the separation membrane. Specifically, it is preferable that the permeation side flow path member 5 is formed of a material having a shape holding force higher than that of the separation membrane, particularly with respect to pressure in a direction perpendicular to the surface direction of the separation membrane. As a result, the permeate-side flow path member 5 can ensure a permeate-side flow path even after repeated water flow or water flow under high pressure.

  For example, as the permeate-side flow path member 5, a tricot, a net-like material having a coarse mesh, a rod shape, a columnar shape, a dot shape, a foamed material, a powdery material, a combination thereof, or the like can be used. The composition is not particularly limited, but from the viewpoint of chemical resistance, ethylene vinyl acetate copolymer resins, polyolefins such as polyethylene and polypolypropylene, resins such as copolymer polyolefins, polyesters, urethanes, and epoxies are preferable, and thermoplastic resins. In addition, a curable resin by heat or light can be used. These can be used alone or as a mixture of two or more. However, since a thermoplastic resin is easy to mold, the shape of the channel material can be made uniform.

  A composite material containing these resins as a base material and further containing a filler is also applicable. The compression elastic modulus of the channel material can be increased by adding a filler such as a porous inorganic material to the base material. Specifically, alkaline earth metal silicates such as sodium silicate, calcium silicate and magnesium silicate, metal oxides such as silica, alumina and titanium oxide, and alkaline earth metals such as calcium carbonate and magnesium carbonate. Carbonate or the like can be used as a filler. In addition, the addition amount of a filler will not be specifically limited if it is a range which does not impair the effect of this invention.

  In the separation membrane 3, more specifically, the base material may be impregnated with the components of the permeation-side flow path member 5. When the flow path material 5 is disposed on the base material side of the separation membrane, that is, the permeation side, and heated from the base material side by a hot melt method or the like, the permeation of the permeation side flow path material 5 proceeds from the back side to the front side of the separation membrane. To do. As the impregnation progresses, the adhesion between the flow path material and the base material becomes stronger, and the flow path material becomes difficult to peel off from the base material even under pressure filtration.

  However, if the components of the permeate-side channel material 5 are impregnated to the vicinity of the separation functional layer (supply-side surface 31), the impregnated channel material destroys the separation functional layer when pressure filtered. . Therefore, when the base material is impregnated with the components of the permeation side flow path member 5, the ratio of the impregnation thickness of the permeation side flow path member 5 to the thickness of the base material (that is, the impregnation rate) is 5% or more and 95% or less. The range is preferably 10% to 80%, and more preferably 20% to 60%. The impregnation thickness refers to the maximum impregnation thickness of the flow path material, and the maximum impregnation thickness of the flow path material means the maximum value of the thickness of the impregnation portion corresponding to the flow path material in one cross section.

  The impregnation thickness of the permeate-side channel material 5 can be adjusted by changing the type of material (more specifically, the type of resin) and / or the amount of material constituting the permeate-side channel material 5, for example. is there. Moreover, when providing the permeation | transmission side flow-path material 5 with a hot-melt method, impregnation thickness can be adjusted also by changing process temperature etc.

  In addition, if the peak resulting from the component of the permeation | transmission side flow path material 5 is obtained separately from a base material by using for the thermal analysis such as differential scanning calorimetry, the base material containing the impregnation part of the permeation side flow path material 5 is obtained. It can be confirmed that the channel material 5 is impregnated in the base material.

  The rate of impregnation of the channel material 5 into the base material is determined by observing the cross section of the separation membrane where the channel material 5 is present with a scanning electron microscope, a transmission electron microscope, or an atomic microscope, The material thickness can be calculated. For example, when observing with a scanning electron microscope, the separation membrane is cut in the depth direction together with the channel material 5, and the cross section is observed with a scanning electron microscope to measure the channel material impregnation thickness and the substrate thickness. And it can calculate from ratio of channel material maximum impregnation thickness and substrate thickness which channel material 5 in a substrate impregnates most. The “base material thickness” when calculating the impregnation depth is the thickness of the base material at the same location as the portion where the maximum impregnation thickness was measured.

  The permeate-side channel material 5 may have a continuous shape or a discontinuous shape.

  As the permeation-side channel material 5, tricot has already been mentioned as an example of a member having a continuous shape. We have already mentioned the definition of continuity. Other examples of the member having a continuous shape include woven fabric, knitted fabric (net, etc.), non-woven fabric, porous material (porous film, etc.) and the like.

  The definition of discontinuity is also as already described. Specific examples of the shape of the discontinuous flow path material include a dot shape, a granular shape, a linear shape, a hemispherical shape, a columnar shape (including a columnar shape, a prismatic shape, and the like), a wall shape, and the like. The plurality of linear or wall-like flow path materials provided on one separation membrane may be arranged so as not to cross each other, and specifically, may be arranged parallel to each other.

  The shape of the individual resin bodies constituting the discontinuous permeate flow path material is not particularly limited, but the flow resistance of the permeate flow path is reduced, and the raw fluid is supplied to and passed through the separation membrane element. It is preferable to stabilize the flow path. For example, an elliptical shape, a circular shape, an oval shape, a trapezoidal shape, a triangular shape, a rectangular shape, a square shape, Examples include parallelograms, rhombuses, and irregular shapes. Further, in the cross section perpendicular to the surface direction of the separation membrane, the permeation side flow path material is provided from the top to the bottom (that is, from the top of the permeation side flow path material in the thickness direction). Toward the separation membrane), the shape may be any of a shape having a wide width, a shape having a narrow width, and a shape having a constant width.

  The thickness of the permeation side channel material in the separation membrane element is preferably 0.03 mm or more and 1 mm or less, more preferably 0.05 mm or more and 0.7 mm or less, further preferably 0.05 mm or more and 0.5 mm or less, Within these ranges, a stable permeate flow path can be secured.

  The thickness of the permeate-side channel material is the required separation characteristics by changing the processing temperature and the hot-melt resin to be selected, for example, when discontinuous permeate-side channel material is placed by the hot melt processing method. And can be adjusted freely to satisfy the conditions of transmission performance.

[4. (Catchment pipe)
The water collecting pipe 2 only needs to be configured so that permeated water flows therethrough, and the material, shape, size, and the like are not particularly limited. As the water collecting pipe 2, for example, a cylindrical member having a side surface provided with a plurality of holes is used.

[5. Method for manufacturing separation membrane element]
(5-1) Manufacture of separation membrane body The manufacturing method of the separation membrane body has been described above, but it is 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 such as chlorine, acid, alkali, nitrous acid, etc. is performed to enhance separation performance and permeation performance as necessary, and the monomer is washed to produce a continuous sheet of the separation membrane body.

(5-2) Arrangement of Supply Side Channel Material The method for manufacturing a separation membrane includes a step of fixing the supply side channel material to the supply side surface of the separation membrane body. This step may be performed at any time during the manufacture of the separation membrane. For example, the supply-side channel material may be provided before the porous support layer is formed on the substrate, or after the porous support layer is provided and before the separation functional layer is formed. It may be provided, or may be performed before or after the above-described chemical treatment is performed after the separation functional layer is formed.

  The method of arranging the channel material is as described above.

(5-3) Formation of Permeation Side Channel Material The same method and timing as the formation of the supply side channel material can be applied to the formation of the transmission side channel material.

  When the permeate-side channel is a continuously formed member such as a tricot, after the separation membrane is manufactured by arranging the permeate-side channel material in the separation membrane body, What is necessary is just to overlap with a road material.

(5-4) Lamination and winding of separation membrane A conventional element manufacturing apparatus can be used for manufacturing a 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.

  An envelope-like membrane is formed by folding and bonding one separation membrane so that the permeation side faces inward or by stacking two separation membranes so that the permeation side faces inward. . As described above, the envelope film is sealed on three sides. 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-shaped film preferably has a viscosity in the range of 40 poise to 150 poise, and more preferably 50 poise to 120 poise. When the separation membrane is wrinkled, the performance of the separation membrane element may be reduced. However, when the adhesive viscosity is 150 poise or less, wrinkles are less likely to occur when the separation membrane is wrapped around the water collection pipe. . Moreover, when the adhesive viscosity is 40 poise or more, the outflow of the adhesive from between the separation membranes is suppressed, and the risk that the adhesive adheres to unnecessary portions is reduced.

  The amount of the adhesive applied is preferably such that the width of the portion to which the adhesive is applied after the separation membrane is wound around the water collecting pipe is 10 mm or more and 100 mm or less. As a result, the separation membrane is securely bonded, and the inflow of the raw fluid to the permeate side is suppressed. Also, a relatively large effective membrane area can be secured.

  As the adhesive, a urethane-based adhesive is preferable. In particular, for the viscosity to be in the range of 40 poise to 150 poise, the adhesive contains an isocyanate as the main agent and a polyol as the curing agent so that the weight ratio of polyol / isocyanate is 1 or more and 5 or less. Is preferred. The viscosity of the adhesive is measured with a B-type viscometer (JIS K 6833) by measuring the viscosity of the main agent, the curing agent alone, and a mixture in which the blending ratio is defined in advance.

  The separation membrane thus coated with the adhesive is arranged so that the closed portion of the envelope-like membrane is located on the inner side in the winding direction, and the separation membrane is wound around the water collecting pipe. Thus, the separation membrane is wound in a spiral shape.

(5-5) Other steps The method of manufacturing a separation membrane element may include further winding a film, a filament, and the like around the outer periphery of the separation membrane wound body 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.

[6. (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 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, raw water can be separated into permeated water such as drinking water and concentrated water that has not permeated through the 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 0.2 to 5 MPa. As the temperature of the raw water supplied increases, the salt removal rate decreases, but the membrane permeation flux decreases as the temperature decreases. Moreover, when the pH of the raw water is in a neutral region, even if the raw water is a high salt concentration liquid such as seawater, the generation of scales such as magnesium is suppressed, and the deterioration of the membrane is also suppressed.

  The fluid to be treated by the separation membrane element is not particularly limited, but when used for water treatment, as raw water, seawater containing 500 mg / L to 100 g / L TDS (Total Dissolved Solids), Examples of the liquid mixture include brine and drainage. In general, TDS refers to the total dissolved solid content, and is expressed as “mass ÷ volume” or “weight 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 to 40.5 ° C., but more simply converted from the practical salt content (S). .

  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.

(Transmission side height)
The average height was analyzed from the measurement result on the transmission side of 5 cm × 5 cm using Keyence high-precision shape measurement system KS-1100. Thirty points with a height of 0.01 mm or more were measured, and the total value of each height was divided by the number of total points.

(Pitch and spacing of supply side channel material)
Using a scanning electron microscope (S-800) (manufactured by Hitachi, Ltd.), 30 sections of any flow channel material were photographed at 500 times. The horizontal distance from the highest part of the high part on the supply side of the separation membrane to the highest part of the adjacent high part was measured at 200 parts, and the average value was taken as the pitch. Moreover, the interval between the latest flow path materials was determined by measuring the shortest distance at 200 locations and calculating the average value.

(Projected area ratio of channel material)
The separation membrane was cut out together with the channel material at 5 cm × 5 cm, and the stage was moved using a laser microscope (selected from 10 to 500 times magnification) to measure the total projected area of the channel material. The projected area ratio obtained by dividing the projected area obtained when the channel material was projected from the separation membrane permeation side or the supply side was taken as the projected area ratio.

(Aspect ratio of channel material)
For one channel material, use a laser microscope (select from 10 to 500 times magnification), move the stage and photograph the upper part of the channel material, and the length (length direction, that is, the maximum size in MD) ) And width (width direction, that is, the maximum value in the CD), and the value obtained by dividing the width by the length was defined as the aspect ratio.

(Water production)
Using a separation membrane or separation membrane element, using saline solution having a concentration of 2,000 mg / L and pH 6.5 as raw water, operating for 100 hours at an operating pressure of 1.5 MPa and an operating temperature of 25 ° C., then sampling for 10 minutes The amount of water permeation (cubic meter) per unit area of the membrane and per day was expressed as the amount of water produced (m3 / day).

(Desalination rate (TDS removal rate))
The TDS concentration of permeated water and raw water sampled by measuring the amount of fresh water 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 raw water)}
In addition, when the measured value after 1 hour and the measured value after 2 hours changed 0.1% or more, the result was added.

Example 1
On a non-woven fabric made of polyethylene terephthalate fibers (yarn diameter: 1 dtex, thickness: about 0.09 mm, air permeability: 1 cc / cm 2 / sec), a 15.0 wt% DMF solution of polysulfone at a thickness of 0.18 mm at room temperature ( 25 ° C.) and immediately immersed in pure water and allowed to stand for 5 minutes to prepare a porous support layer (thickness: 0.13 mm) roll made of a fiber-reinforced polysulfone support membrane.

  Thereafter, the porous support layer roll was unwound and immersed in a 2.2 wt% aqueous solution of m-PDA on the polysulfone surface for 2 minutes, and the support membrane was slowly pulled up in the vertical direction. Nitrogen was blown from the air nozzle to remove the excess aqueous solution from the surface of the support film, and then an n-decane solution containing 0.196% by weight of trimesic acid chloride was applied so that the surface was completely wetted and allowed to stand for 1 minute. Thereafter, excess solution was removed from the membrane by air blowing, washed with hot water at 85 ° C., drained by air blowing, and a separation membrane body wound in a roll shape was obtained.

  Next, a supply-side channel material having the form shown in FIG. 19 was formed on the supply-side surface of the separation membrane main body (that is, the surface to which the n-decane solution was applied). Specifically, a polyolefin hot melt adhesive (trade name: PHC-9275, manufactured by Sekisui Fuller) was used at a resin temperature of 140 ° C. and a running speed of 5 while using a gravure roll and adjusting the temperature of the backup roll to 20 ° C. It applied to the separation membrane main body at 0 m / min.

  The planar shape of the high channel material 41A is an ellipse, the height of the high channel material 41A is 0.7 mm, the length is 0.5 mm, the aspect ratio is 2, and the pitch in the length direction is It was 3 mm. The angle formed by the two high flow path materials 41A close to the flow direction of the raw water is 90 ° (described as the formation angle in the table), and in the region between 70 μm from the membrane surface, the supply side flow The width of the road material increased as it approached the membrane surface.

  Moreover, the planar shape of the low flow path material 41B was a circle, the height was 0.25 mm, the length was 0.4 mm, and the aspect ratio was 1. The low flow path materials were arranged one by one between the two high flow path materials 41A so as to be located in the middle in the length direction. The width between 70 μm from the film surface spread in the height direction.

  In addition, the high flow path material and the low flow path material were formed so as to be arranged on only one of the two supply-side surfaces facing each other in the separation membrane leaf.

  The separation membrane on which the dots were arranged was cut out to 43 cm 2, put in a pressure vessel, and operated under the above-mentioned conditions.

  The results of Examples and Comparative Examples are shown in Tables 1 to 3 below.

(Example 2)
The separation membrane roll obtained in Example 1 was folded so that the effective area of the separation membrane element was 37.0 m 2 and further cut to obtain a separation membrane leaf having a width of 1,000 mm. As described above, the high flow path material and the low flow path material are disposed only on one of the supply-side surfaces facing each other in the separation membrane leaf.

  Twenty-six separation membrane leaves are stacked with a tricot (thickness: 0.3 mm, groove width: 0.2 mm, ridge width: 0.3 mm, groove depth: 0.105 mm) as the permeate side channel material It was.

  Twenty-six separation membrane leaves are stacked with a tricot (thickness: 0.3 mm, groove width: 0.2 mm, ridge width: 0.3 mm, groove depth: 0.105 mm) as the permeate side channel material It was. The obtained laminated pair was spirally wound around a water collecting pipe made of ABS (width: 1,020 mm, diameter: 30 mm, number of holes 40 x one straight line). Further, a film was wound around the outer periphery and fixed with tape, and then edge cutting, end plate attachment, and filament winding were performed to produce an 8-inch element. The effective membrane area of the separation membrane element was 37.0 m2.

  When the element was put in a pressure vessel and operated under the above-mentioned conditions, the amount of water produced and the desalting rate were 31.2 m 3 / day and 98.7%.

(Example 3)
A separation membrane was prepared in the same manner as in Example 1 except that the angle formed between the two high flow path members 41A adjacent to the flow direction of the raw water of the high flow path member 41A was 25 °.

  Thereafter, an 8-inch element was produced in the same manner as in Example 2.

  When the element was put in a pressure vessel and operated under the above-mentioned conditions, the amount of water produced and the desalting rate were 28.5 m 3 / day and 99.1%.

Example 4
A separation membrane was prepared in the same manner as in Example 1 except that the angle formed between the two high flow path members 41A adjacent to the flow direction of the raw water of the high flow path member 41A was 150 °.

  Thereafter, an 8-inch element was produced in the same manner as in Example 2.

  When the element was put in a pressure vessel and operated under the above-mentioned conditions, the amount of water produced and the desalting rate were 32.6 m 3 / day and 98.0%.

(Example 5)
A separation membrane was prepared in the same manner as in Example 1 except that the aspect ratio of the high flow path material 41A was set to 1.

  Thereafter, an 8-inch element was produced in the same manner as in Example 2.

  When the element was put in a pressure vessel and operated under the above-mentioned conditions, the amount of water produced and the desalting rate were 30.9 m 3 / day and 99.0%.

(Example 6)
A separation membrane was prepared in the same manner as in Example 1 except that the aspect ratio of the high flow path material 41A was set to 10.

  Thereafter, an 8-inch element was produced in the same manner as in Example 2.

  When the element was put in a pressure vessel and operated under the above-mentioned conditions, the amount of water produced and the desalination rate were 31.7 m 3 / day and 98.4%.

(Example 7)
A separation membrane was prepared in the same manner as in Example 1 except that the height of the high flow path material 41A was 0.45 mm.

  Thereafter, an 8-inch element was produced in the same manner as in Example 2.

  When the element was placed in a pressure vessel and operated under the above-mentioned conditions, the amount of water produced and the desalting rate were 27.0 m 3 / day and 99.0%.

(Example 8)
A separation membrane was prepared in the same manner as in Example 1 except that the height of the high flow path material 41A was 1.6 mm.

  Thereafter, an 8-inch element was produced in the same manner as in Example 2.

  When the element was put in a pressure vessel and operated under the above-mentioned conditions, the amount of water produced and the desalting rate were 32.9 m 3 / day and 98.1%.

Example 9
A separation membrane was prepared in the same manner as in Example 1 except that the height of the low flow path material 41B was 0.05 mm.

  Thereafter, an 8-inch element was produced in the same manner as in Example 2.

  When the element was put in a pressure vessel and operated under the above-described conditions, the amount of water produced and the desalting rate were 32.0 m 3 / day and 98.0%.

(Example 10)
A separation membrane was prepared in the same manner as in Example 1 except that the height of the low flow path material 41B was 0.4 mm.

  Thereafter, an 8-inch element was produced in the same manner as in Example 2.

  When the element was placed in a pressure vessel and operated under the above-described conditions, the amount of water produced and the desalting rate were 31.0 m 3 / day and 98.7%.

(Example 11)
A separation membrane was prepared in the same manner as in Example 1 except that the low flow path material 41B was continuous in the length direction as shown in FIG.

  Thereafter, an 8-inch element was produced in the same manner as in Example 2.

  When the element was put in a pressure vessel and operated under the above-described conditions, the amount of water produced and the desalting rate were 30.0 m 3 / day and 99.2%.

(Example 12)
A separation membrane roll was produced in the same manner as in Example 1 except that the end channel material was provided at both ends on the supply side of the separation membrane main body. As an end channel material, hot melt was applied in a stripe shape with an oblique angle of 40 °, a line width of 1 mm, a height of 0.415 mm, and a pitch of 3 mm. The region where the end channel material was formed was a strip shape as shown in FIG. 2, and the width of the strip region was 40 mm. Further, the belt-like region was formed so as to overlap each other on both of the two separation membranes facing each other on the supply side surface. The total height of the overlapping end channel materials was 0.83 mm.

  The dots were provided only on one of the supply-side surfaces facing each other when incorporated in the element, and the end channel material was provided on both the supply-side surfaces facing each other.

  Thereafter, an 8-inch element was produced in the same manner as in Example 2.

  When the element was put in a pressure vessel and operated under the above-mentioned conditions, the amount of water produced and the desalting rate were 30.6 m 3 / day and 99.0%.

(Example 13)
An envelope membrane that is perpendicular to the longitudinal direction of the water collection tube when used as a separation membrane element using an applicator loaded with a comb-shaped shim having a slit width of 0.5 mm and a pitch of 1.0 mm on the separation membrane permeation side instead of a tricot In this case, the ethylene vinyl acetate copolymer resin is linear from the inner end to the outer end in the winding direction so as to be perpendicular to the longitudinal direction of the water collecting pipe and the temperature of the backup roll is adjusted to 20 ° C. (Product name: 701A) was applied linearly at a resin temperature of 130 ° C. and a running speed of 5.5 m / min, with a height of 0.3, a channel material width of 0.9 mm, and a channel material in the longitudinal direction of the water collecting pipe A channel material having an interval of 0.5 mm, a pitch of 1.0 mm, and a projected area ratio of 0.50 was fixed to the entire separation membrane.

  Using the separation membrane roll thus obtained, an 8-inch element was produced in the same manner as in Example 2.

  When the element was put in a pressure vessel and operated under the above-described conditions, the amount of water produced and the desalting rate were 34.2 m 3 / day and 98.5%.

(Example 14)
A separation membrane roll was produced in the same manner as in Example 1 except that the base material was changed to a long fiber nonwoven fabric. The fiber orientation degree of the substrate was 20 ° on the surface layer on the porous support layer side and 40 ° on the surface layer on the side opposite to the porous support layer. The dots were provided only on one of the supply-side surfaces facing each other when incorporated in the element, and the band-like regions were provided on both the supply-side surfaces facing each other.

  Using the separation membrane roll thus obtained, an 8-inch element was produced in the same manner as in Example 2.

  When the element was put in a pressure vessel and operated under the above-mentioned conditions, the amount of water produced and the desalting rate were 31.5 m 3 / day and 98.7%.

(Example 15)
Other than changing the backup roll temperature to 5 ° C. and further reducing the width of the supply channel material as it approaches the membrane surface in the region of 70 μm from the membrane surface in the high channel material 41A and the low channel material 41B Were prepared in the same manner as in Example 1.

  Thereafter, an 8-inch element was produced in the same manner as in Example 2.

  When the element was put in a pressure vessel and operated under the above-mentioned conditions, the amount of water produced and the desalting rate were 28.2 m 3 / day and 98.0%.

(Example 16)
Separation membrane as in Example 1 except that the backup roll temperature was changed to 12 ° C. and the width of the high flow channel material 41A and the low flow channel material 41B was constant in the height direction between 70 μm from the membrane surface. Was made.

  Thereafter, an 8-inch element was produced in the same manner as in Example 2.

  When the element was put into a pressure vessel and operated under the above-mentioned conditions, the amount of water produced and the desalting rate were 30.0 m 3 / day and 98.3%.

(Examples 17 to 20)
A separation membrane was prepared in the same manner as in Example 1 except that the gravure roll was changed and the shape of the low flow path material 41B was as shown in Tables 3 and 4.

  Thereafter, an 8-inch element was produced in the same manner as in Example 2.

  When the element was placed in a pressure vessel and operated under the above-mentioned conditions, the amount of water produced and the desalination rate were as shown in Tables 3 and 4.

(Comparative Example 1)
All except that discontinuous channel material is not arranged on the supply side, and a net (thickness: 0.7 mm, pitch: 4 mm × 4 mm, fiber diameter: 0.35 mm, projected area ratio: 0.20) is used. A separation membrane roll was produced in the same manner as in Example 2.

  When the element was put in a pressure vessel and operated under the above-mentioned conditions, the amount of water produced and the desalting rate were 27.5 m 3 / day and 99.0%.

(Comparative Example 2)
A separation membrane roll was produced in the same manner as in Example 2 except that the low flow path material 41B was not arranged.

  Using the separation membrane roll thus obtained, an 8-inch element was produced in the same manner as in Example 2.

  When the element was put in a pressure vessel and operated under the above-mentioned conditions, the amount of water produced and the desalting rate were 31.3 m 3 / day and 94.9%.

  As is clear from the results, the separation membrane and the separation membrane element of the examples have high water production performance, stable operation performance, and excellent removal performance.

  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 Water collecting pipe 21 End part on the upstream side of the separation membrane element 22 End part on the downstream side of the separation membrane element 3 Separation membrane 30 Separation membrane body 31 Surface on the supply side of the separation membrane 32 Surface on the permeation side of the separation membrane 33, 34 Band-like region 41A, high flow channel material 41B low flow channel material 42 end flow channel material 5 permeate side flow channel material 6 envelope-shaped membrane 7 upstream end plate 8 downstream end plate 101 raw water 102 permeate water 103 Concentrated water H1 Height of the high flow path material H2 Height of the low flow path material W0 Width of the separation membrane in the longitudinal direction (width direction) of the water collecting pipe W1, W2 Width of the band-like region in the same direction

Claims (7)

A separation membrane body having a supply side surface and a permeate side surface;
A plurality of high flow path materials fixed on the supply side surface of the separation membrane main body and having a height H1 of 0.45 mm to 2 mm;
A low flow path material that is fixed to the supply-side surface of the separation membrane body, has a height H2 of 0.03 mm to 0.4 mm, and is disposed between the high flow path materials;
A separation membrane comprising: The separation membrane according to claim 1, wherein a height H1 of the high flow path material and a height H2 of the low flow path material satisfy 0.1 ≦ (H2 / H1) ≦ 0.9. 3. The separation membrane according to claim 1, wherein an aspect ratio of at least one of the high flow path material and the low flow path material is 1 or more and 15 or less in plan view. The angle formed by a straight line connecting the high flow path material and two high flow path materials adjacent to the high flow path material in the flow direction of the raw water is 20 ° or more and 160 ° or less. The separation membrane according to any one of the above. The separation membrane according to any one of claims 1 to 4, wherein the low flow path material is disposed so as to be continuous between the two high flow path materials.   2. At least a part of the separation membrane is provided with a belt-like region to which an end channel material is fixed at least at one end in the longitudinal direction of the water collecting pipe on the supply side surface of the separation membrane main body. The separation membrane according to any one of -5. Water collecting pipe,
The separation membrane element containing the separation membrane in any one of Claims 1-6 wound around the said water collection pipe | tube.