JPH07111261B2 - Humidification method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a humidification method, and more specifically, not only for air conditioning of general buildings but also for food production, storage, or maintenance of precision machines, computers, and the like. The present invention relates to an ion exchange membrane for humidifying by selectively allowing water and water vapor to pass therethrough when keeping constant temperature and humidity conditions.

[Prior Art] In recent years, the demand for humidification has been increasing due to the development of advanced industries, the innovation of distribution systems, and the progress of storage technology.
Clean one, highly humidified one, highly durable one, easy maintenance one according to industrial application,
Diversification is progressing according to various purposes such as low initial and running costs.

Conventionally, there are the following methods for humidifying air.

(1) Steam blowing method: A method of blowing steam and absorbing it in air.

(2) Water mist method: A method in which water is atomized and blown out and vaporized in the air.

(3) Vaporization method: by increasing the contact area between water and air,
How to vaporize water.

(4) Humidification membrane method: Air to be humidified is brought into contact with one surface of the membrane, and water or high humidity air is applied to the other surface (for example, (2) above).
-(3) The humidified air obtained in (3) is brought into contact with water vapor to selectively permeate the air to be humidified.

The steam blow-out method of (1) is capable of clean humidification by removing impurities such as bacteria and scaly components contained in water, and has the feature that it does not lower the air temperature, but it heats water. It requires electric power, and since the vapor residue remains white around the humidifier, it has the drawback of requiring frequent maintenance such as frequent cleaning.

(2) In the water spray method, water is atomized by jetting force, ultrasonic vibration, etc., so there is an advantage that the power is small, but on the other hand,
Since bacteria in water and scaly components are scattered in the air,
When using it for air conditioning in intelligent buildings such as computer rooms, care must be taken depending on the air cleanliness of the operating environment. In general, these measures include:
A water treatment device is provided. However, the deionizer absorbs inorganic ions and releases H ₂ O by an ion exchange method, but cannot remove organic substances such as fungi. further,
Since the water softener only replaces the chlorine component, which is easy to deposit as scale, with Na ions, which is hard to deposit, when the water obtained by using it is used in a water spray humidifier, organic substances such as fungi, sodium salts, etc. Inorganic substances will be released. Neither water treatment device can solve the above problems. Further, since water is sprayed, there is a drawback that the air temperature is lowered.

(3) In the case of the vaporization type, since it blows out at a relative humidity of 100% or less, there is a feature that condensation is not necessary even if there is an obstacle near the humidifier, but on the other hand, evaporation residue adheres to the humidifier. It has a maintenance drawback that it needs to be cleaned in order to maintain its humidifying ability, and it is less likely to release impurities in the water than the steam blowing type or water spraying type, but it is a highly clean humidifying type such as the electronics industry. It is not always sufficient for areas where air is required.

(4) In the case of the humidification membrane type, since it is humidified through a membrane that selectively permeates with water vapor, clean humidified air can be obtained, but it has a large water vapor permeability and durability, particularly, bacteria resistance, Not used industrially due to lack of mold resistant film. That is, as a membrane having a large water vapor permeability, hydrous polymers such as cellulose and polyvinyl alcohol are known, but these membranes have a large water vapor permeability, but are decomposed by bacteria or mold in water. It cannot be used for a long time.

Further, as a membrane permeable to water and water vapor, an ion exchange membrane containing an ion exchange group is known. These membranes are supposed to be used in water, so there is no problem with durability, but conventional ion-exchange membranes use membranes with high ion selective permeability and low water permeability. However, it cannot be used as it is.

As a humidifying membrane type that overcomes the drawbacks of these water-containing polymer membranes, a method using a hydrophobic microporous membrane that does not allow water to permeate but allows water vapor to pass has been proposed.

For example, in JP-A-61-72948 and JP-A-61-250429, water and air are not brought into direct contact with each other, but water and air are partitioned through a porous membrane, and water vapor is allowed to permeate into the porous membrane. However, as long as the material is ceramic or organic polymer, as long as it is a porous film, it is necessary to prevent fungus that adheres and propagates during use as a humidification film. I can't. When mold develops in the porous material structure,
This will block the water vapor permeation path, lowering the humidifying capacity, and if the humidifier is used for building air conditioning, it will cause mold spores to diffuse into the building, which is a sanitary problem. Also, in the first place, if a hydrophobic porous material is used in order to prevent water from permeating, this material becomes a low water vapor permeation antibody and has a low humidification capacity, and in order to obtain large humidification, the surface area of the porous membrane is large. The size of the device becomes large.

[Problems to be Solved by the Invention] The present invention is intended to solve the above-mentioned drawbacks of the prior art, and an object of the present invention is to provide a humidifying method having a high water / water vapor permeation rate. . More specifically, it is an object of the present invention to provide a long-life water / steam permeation humidification method which is clean, has a large humidification capacity, can be easily made into a device, and can be reduced in operating cost.

[Means for Solving the Problem] As a result of earnest efforts to solve the above-mentioned problems, as a result, an ion-exchange membrane having a different membrane structure and physical properties from the conventional ion-selective permeable ion-exchange membrane was used as a humidifying membrane. The present inventors have found that the method used as is extremely effective and completed the present invention.

The above-mentioned object of the present invention is that the fixed ion concentration is 0.5 to 6 N, the water absorption rate is 40 to 150% by volume, the ion exchange resin capacity is 0.6 to 2.5 meq / g, and the water vapor transmission rate is composed of an ion exchange layer.
100 Nm ³ / m ²・ hr ・ atm or more, preferably 120 Nm ³ / m ²・ hr ・ a
Achieved by using a humidifying membrane with tm or more.

The humidifying membrane used in the present invention basically controls the fixed ion concentration, water absorption rate, and ion exchange capacity of the ion exchange membrane within a specific range.

As the humidifying membrane of the present invention, fixed ion exchange concentration 0.5 ~ 6N,
Preferably, 1 to 4N is used. The fixed ion concentration is expressed in milliequivalents of ion exchange groups per 1 g of water absorbed by the membrane. In the development of conventional ion-selective permeable ion exchange membranes, it has been promoted in the direction of increasing the fixed ion concentration from Donnan's equilibrium equation showing the ion-selective permeability, and normally, the fixed ion concentration of 6 N or more is preferably used. There is. From the research of the present invention, as a water vapor permeable ion exchange membrane, when the fixed ion concentration exceeds 6 N, the water vapor transmission rate is remarkably decreased, and when it is 0.5 N or less, the water vapor transmission rate is decreased and the water content is contained in water. It was found that impurities such as bleaching ingredients permeate the membrane.

The reason why the fixed ion concentration is important for water vapor permeability has not been elucidated, but it is probably because of the following reasons. The water in the ion-exchange membrane has different properties from ordinary water due to the interaction with the ion-exchange group, and the strength of the interaction causes the presence of antifreeze water, bound water, and free water. Are believed to be present. It is considered that when the fixed ion concentration becomes high, the adsorbed water is firmly bound to the ion exchange group, the movement of water in the membrane is reduced, and the permeation rate becomes low.

In the present invention, it is important to keep the water absorption rate and the ion exchange capacity within a specific range in addition to the fixed ion concentration in order to obtain a membrane having a high water vapor transmission rate. Water absorption rate is 40% by volume
In the following, the water vapor permeation rate is lowered, and if it exceeds 150% by volume, the ability to retain the film shape is impaired, so that the water absorption rate is 40 to 150% by volume, particularly 50 to 100% by volume. It is preferable because it has a practical strength in manufacturing and using the module. On the other hand, the ion exchange capacity is 0.6
~ 2.5 meq / g resin, preferably 1.0-2.0 meq / g
g resin is preferable for obtaining a film having an excellent water vapor transmission rate and for obtaining film strength. Even with a membrane having an ion exchange capacity of 1.0 meq / g resin or less, the fixed ion concentration of the present invention is 1 to 1.
The water absorption rate can be 6 N and the water absorption rate can be 40% by volume or more, but from the viewpoint of water vapor permeability, it is preferable that the ion exchange capacity is 1.0 meq / g resin or more and the amount of ion exchange groups is large.

As described above, as the ion exchange group of the humidifying membrane used in the present invention, a sulfonate group, a sulfonate group, a carboxylic acid group, a carboxylate group, a phosphate group, a phosphate group, a phosphate salt, an acidic hydroxyl group, an acidic hydroxyl group. In addition to cation exchange groups such as salts, 1-
Examples thereof include anion exchange groups such as a tertiary amino group and a quaternary ammonium group. Among them, the sulfonic acid group has high water absorption and little deterioration due to a chlorine component contained in water, heat resistance, It is particularly preferable because it has excellent chemical resistance.

As the material of the humidifying film, styrene-based resin, ethylene-based resin, polysulfone-based resin, fluorine-containing resin and the like can be used without any limitation, but heat resistance, chemical resistance, molding processability, and mechanical properties, especially From the viewpoint that there is no film damage due to swelling or shrinking, sulfonic acid film made of fluorine-containing resin, especially the general formula A fluorine-containing copolymer containing (m = 0 or 1, n = integer of 2 to 5) is preferable.

Examples of the above-mentioned fluorine-containing copolymer include fluorinated olefins such as tetrafluoroethylene, trifluoroethylene, vinylidenefluorite "and vinyl fluoride, and a general formula Those obtained by copolymerizing a SO ₃ F group-containing perfluorovinyl ether monomer represented by (m = 0 or 1, and n = integer of 2 to 5) are preferable. Further, if necessary, a third component such as ethylene, propylene, perfluorovinyl ether, perfluorodivinyl ether, perfluoroallyl vinyl ether may be added.

The composition ratio of the copolymer is such that the fluorine-containing copolymer is
Ion exchange capacity is chosen to form 1.0-2.5 meq / g resin.

As the humidifying film of the present invention, the above copolymer is used in the form of a film by a known means. The surface of such a film usually has a smooth surface. However, as the humidifying film of the present invention, by making at least one surface of the humidifying film that is in contact with the gas to be humidified a rough surface, the permeation rate of water vapor can be increased. Can be increased. Here, the term “roughened” means that the surface of the film is irregular, that is, the surface of the film is not completely smooth and has fine irregularities, and for example, the film is “Having a surface roughness of 2 μm” means that the height of a peak of a certain peak and the valley adjacent to it in the unevenness of the surface of the film is 2 μm on average. Further, the surface area used in the present specification, on the two sides orthogonal to the stylus type surface roughness meter, obtain the surface length between any two points,
It is obtained by multiplying the linear length between the two points by the magnification on each side.

As the method for obtaining the roughened humidified film in the present invention, when the humidified film or the precursor of the humidified film has thermoplasticity,
Other materials having a rough surface such as a blast metal plate or roll, a blast film, a porous metal plate or a porous film can be used for transfer. In addition to mechanically roughening the surface of the humidifying film with an abrasive such as sandblasting, or chemically roughening in an ionizing atmosphere such as plasma etching or sputtering, roughening the polymer solution or monomer solution. A method of obtaining a rough semi-permeable membrane by casting or polymerizing on the surface is used. As another preferred roughening method, soluble particles and fibers are embedded in a semipermeable membrane, or an ion-exchangeable polymer solution containing soluble particles and fibers is applied to a humidifying membrane of a base material, and then the soluble membrane is dissolved. A method of eluting particles and fibers to roughen the surface can also be used.

The surface-roughened semipermeable membrane thus obtained has a surface roughness of 0.
5 to 100 μm, preferably 1 to 50 μm, and the fine irregularities have an average of 10 ³ to 10 ⁵ pieces, preferably an average of 10 ⁵ to 10 ¹² pieces per 1 cm ² of the film area, so that the roughened surface area is , The projected area (ie, the surface area of an ideal smooth film), 5
It is formed so as to be doubled or more, preferably 10 times or more. When the surface roughness is as large as 100 μm or more, the amount of impurities that do not want to permeate through the recess with the thinnest film thickness increases, resulting in a decrease in selective permeability or a decrease in gas flowability to the recess. However, this leads to a decrease in the humidification rate. For the same reason, it is preferable that the ratio of the film thickness between the concave portion and the convex portion of the humidifying film is 1/2 or more.

The humidifying film of the present invention can be used alone by processing the above-mentioned copolymer having specific physical properties into a film, but also has an increased humidification rate and practical strength. In addition, a reinforcing material made of a porous substrate can be used.

The porous substrate used in the present invention has a pore size of 0.01 to 10
Those having a thickness of 0 μm, a thickness of 10 to 500 μm, and having hydrophilic surfaces and inner walls are used. When the porous base material is used on the side that comes into contact with water, it is a matter of course that it has hydrophilicity. However, even when the porous base material is used on the side that comes into contact with the substrate to be humidified, The inner wall preferably has hydrophilicity. Conventionally, in the humidifying film by the hydrophobic microporous film,
The hydrophobic porous layer is known as a separation membrane that does not allow water to permeate but only water vapor, but according to the study of the present inventor, the water vapor permeability of the porous body layer whose inner wall is hydrophilized is:
It is remarkably improved as compared with the porous body layer having a hydrophobic surface.

It is not clear why the permeability of gaseous water vapor is improved by imparting hydrophilicity to the inner wall of the porous body layer, but it is considered to be due to the following reasons.

That is, in the humidifying membrane, it is considered that when the water vapor permeating from the water side permeates the porous substrate, the water vapor inside is saturated. Saturated water vapor condenses as water when the temperature decreases, but when water condenses in the hydrophobic porous body, it blocks the pores and consequently reduces the water vapor permeability, but when the inner wall is hydrophilic. It is explained that condensed water is adsorbed on the hydrophilic layer, the pores are not clogged, and the water vapor permeability is high.

However, such description is provided for the understanding of the present invention and does not limit the present invention in any way.

As the porous substrate used in the present invention, those having durability such as dimensional stability against water and humidity, mechanical strength, chemical resistance, and mold resistance can be used without limitation, and preferable examples include: Woven cloth, non-woven cloth and microporous body made of polytetrafluoroethylene, ethylene tetrafluoride-ethylene copolymer, fluoropolymers such as vinylidene fluoride, olefin polymers such as polyethylene and polypropylene, and carbon fiber Is exemplified.

When the porous substrate itself does not have hydrophilicity, hydrophilicity is imparted to the surface before or after lamination with the ion exchange layer. Hydrophilicity is preferably achieved by coating a hydrophilic layer of a surfactant, a water-soluble polymer, a water-absorbing polymer, etc., but the effect of improving durability and water vapor transmission rate by imparting a hydrophilic layer is large. A coating of ion exchange resin having a rate of 40% by volume or more is preferable. The hydrophilic layer is obtained by impregnating a porous substrate with an ion-exchange resin monomer and polymerizing it to coat the inner wall of pores of the porous substrate, or impregnating a solution of an ion-exchange resin into the pores, and drying. It is preferable because it is easy to manufacture. The hydrophilic layer covering the pore walls is made to adhere so as to occupy 0.1 to 50% by volume of the void volume of the porous body. When it is less than 0.1%, the effect of improving the water vapor permeability is not exhibited, and when it is 50% or more, the pores of the porous layer are clogged and the permeability is lowered, which is not preferable. More preferably, 0.5 to 10% by volume is attached.

As a composite method of the porous substrate and the ion exchange resin membrane,
After forming the ion exchange resin into a membrane, it is laminated with a porous substrate, or the ion exchange resin is a solution, suspension solution, emulsion polymerization latex, or an organic solvent system in which the water of the emulsion polymerization latex is replaced with an organic solvent. An example is a method of impregnating a porous substrate with a dispersion or the like and drying.

In particular, when a hollow porous layer is used, a hollow system for dehumidification having a large permeation amount can be obtained by a method of impregnating the above-mentioned resin-containing solution into the hollow system and drying.

When the membrane thus obtained is not converted into an ion exchange group, it is hydrolyzed with an alkaline solution and then immersed in an acidic solution to obtain a sulfonic acid type humidified membrane.

In the present invention, the fixed ion concentration of the obtained ion exchange resin layer, in order to make the water absorption within a certain range, the hydrolysis conditions of the membrane, the treatment with an acidic solution, and when the sulfonic acid resin solution is cast-coated, However, the drying conditions are often important. If the ion exchange capacity is about 1.1 meq / g resin, after hydrolysis with 10-20 wt% alkaline aqueous solution, 0.1
The moisturizing membrane of the present invention can be obtained by acidifying with a 5N acidic solution, washing with water at room temperature, and then air-drying. Also, if the ion exchange capacity is 1.5 meq / g resin or more, hydrolysis,
After acidification and washing with water, it may be preferable to heat the membrane at 50 ° C, preferably 100 ° C or higher. in any case,
A high-performance humidifying membrane can be obtained by appropriately selecting the treatment conditions so that the fixed ion concentration and water absorption of the present invention can be obtained.

When water is brought into contact with one side of the membrane thus treated and air to be humidified is made to flow to the opposite side, the water is absorbed in the membrane and the water is evaporated on the air side of the membrane so that humidification can be performed. The driving force in this case is the water vapor partial pressure difference across the membrane. The water vapor partial pressure on the water side of the membrane is considered to correspond to the saturated water vapor pressure at that temperature.

The shape of the membrane may be flat or hollow. In the case of a hollow structure, water may flow in the hollow and air may flow outside, or vice versa, water may flow outside and air may flow inside. In addition, it suffices to flow water in an amount more than that which is reduced by permeation. Also, it should be noted that the water to be supplied can be sufficiently clean and humidified even if it is tap water. This is because only ions in the Donnan equilibrium are present in the membrane, water evaporates on the air side of the membrane, and there is no permeation of organic matter, so to speak, it is possible to perform clean humidification beyond the conventional vaporization humidification. It will be possible. of course,
Water treated with a water treatment device such as a water purifier may be used.

Next, the present invention will be described by way of examples, but the present invention is not limited to such examples. Prior to the examples, various measuring methods used in the following examples will be collectively described.

(1) Measurement of water absorption W Membrane manufactured under the same conditions as the membrane whose permeability is measured, or a membrane taken from a part of the measurement membrane, is immersed in pure water at 25 ° C to reach equilibrium. The weight is W ₁ , and the dry weight W ₂ obtained by vacuum drying the film is calculated from the following formula. ρ is the density of the ion exchanger layer.

W = 100 (W ₁ −W ₂ ) ・ ρ / W ₂ (2) Calculation of fixed ion concentration A _{W From} the ion exchange capacity (milliequivalent / g resin) A _R and the above water absorption measurement data, Ask.

A _W = A _R / {(W ₁ −W ₂ ) / W ₂ } (3) Measurement of water vapor transmission rate Q Membrane area 40 cm ² (20 cm × 2 cm), cross-sectional area 1.2 cm ² (0.6 cm)
× 2 cm) with a membrane in a two-chamber cell, one chamber was supplied with clean water at 50 ml / min, and the other chamber was supplied with air with a dew point of -30 ° C of 12 / m.
Flow at in (2m / s). At this time, the water temperature, the air side outlet relative humidity, and the air side outlet temperature were measured, and the water vapor transmission rate Q (Nm ³ /
m ² · hr · atm) is calculated from the following equation.

Q = q × P _A / A / △ P where q = flow rate (m ³ / hr) P _A : Air side outlet water vapor pressure (mmHg) P _A = P ′ _W × RH / 100 where P ′ _W : Saturated water vapor pressure at the air side temperature (mmHg) RH: Relative humidity (%) A: Membrane area (m ² ) △ P: Water vapor pressure difference through the membrane (atm) △ P = -P _A / 1n {P _W −P _A ) / P _W } / 760 where P _W : water vapor pressure (mmHg) [Example] Example 1 Tetrafluoroethylene and CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ SO ₂ F
And were copolymerized to obtain a copolymer A having an ion exchange capacity of 1.10 meq / g resin. The copolymer A was melt-extruded to obtain a flat film having a thickness of 50 μm.

The membranes was hydrolyzed to the potassium sulfonate with 20 wt% caustic aqueous potassium was immersed in 1N hydrochloric acid, -SO ₃ H
It was converted to a mold, washed with water, and then air-dried.

The physical properties and water vapor transmission rate of the film are shown in Table 1.

Example 2 Copolymer A having a thickness of 50 μm shown in Example 1 was hydrolyzed to a potassium sulfonate salt with a 20% by weight aqueous solution of potassium hydroxide and then immersed in an aqueous 1N calcium chloride solution to form a calcium salt type. , Boiled in ion-exchanged water. Example 1
The water vapor transmission rate was measured in the same manner as in. The results are shown in Table 1.
It was shown to.

Example 3 Tetrafluoroethylene and CF ₂ = CFO (CF ₂ ) ₃ COOCH ₃ were copolymerized to give an ion exchange capacity of 1.
A copolymer B having 80 meq / g resin was obtained. The copolymer B was melt-extruded to obtain a flat film having a thickness of 50 μm.

The membrane was hydrolyzed with an aqueous solution of caustic soda to form a sodium carboxylic acid salt, and boiled in ion-exchanged water. Table 1 shows the physical properties of this membrane and the water vapor transmission rate measured by the same method as in Example 1.

Comparative Example 1 Using the same cell as in Example 1, the membrane is not sandwiched, and clean water is allowed to flow to one chamber side, and dry air is allowed to flow directly onto this free water surface. The humidification rate at this time is shown in Table 1. From this result, it was found that the membrane of Example 1 had a moisturizing ability equivalent to that of the free water surface.

Comparative Example 2 The flat film of the same copolymer B as in Example 3 was hydrolyzed in the same manner as in Example 1 to obtain an acid-COOH air-dried film. Table 1 shows the physical properties of this membrane and the water vapor transmission rate measured by the same method as in Example 1.

Comparative Example 3 Hydrocarbon-based ion-exchange membrane, Selemion CMV (manufactured by Asahi Glass) was immersed in a sodium chloride aqueous solution to form Na type,
The water vapor transmission rate was measured under the same conditions as in Example 1. The results are shown in Table 1.

Example 4 A multifilament having a denier number of 60, which is obtained by aligning and twisting 6 monodenier filaments of 10 denier made of polytetrafluoroethylene, is used as a warp, and the same monofilament 10 is used.
Example 1 A porous base material of a woven fabric having a thickness of 60 μm, in which a multifilament having a denier number of 100, which is aligned and twisted, is used as a weft yarn and entangled and woven at a warp yarn density of 50 yarns / inch and a weft yarn density of 25 yarns / inch, Example 1 The membrane inserted inside the membrane shown in 1 above was treated and measured under the same conditions as in Example 1. The water vapor transmission rate was 165 Nm ³ / m ² · hr · atm, which was equivalent to that of the membrane of Example 1.

Example 5 The copolymer A shown in Example 1 was used to obtain an inner diameter of 2.7 mm and an outer diameter of 3.0 mm.
It was a hollow tube. The membrane was immersed in an 11 wt% caustic potassium-30 wt% dimethylsulfoxide aqueous solution at room temperature for 40 hours, immersed in 1N hydrochloric acid to make the membrane an acid form, and then air-dried.
Bunden 10 of these and store them in a vinyl chloride tube with an inner diameter of 20 mm.
I made a module. Water was passed through the hollow tube, dry air was flown outside the hollow tube, and the water vapor permeation rate was measured to be 170 Nm ³ / m ² · hr · atm, which is equivalent to that of the membrane of Example 1. It was performance. .

Comparative Example 4 The copolymer A obtained in Example 1 was melt-extruded to give
A flat film having a thickness of 500 μm was obtained. Other than that, when the water vapor transmission rate was measured in the same manner as in Example 1, it was 30 Nm ³ / m ²
・ It was hr ・ atm.

Example 6 The copolymer A obtained in Example 1 was melt-extruded to give
A roughened film having a thickness of 80 μm was obtained by transferring a rough surface having a surface roughness of 5 μm on one surface.

After hydrolysis the membrane in the same manner as in Example 1, were converted into -SO ₃ H type, washing with water, and dried. When the surface area of the film was determined by a surface roughness meter, it was 16 times the projected area. The water absorption rate and fixed ion concentration of the membrane were the same as in Example 2.
The results of measuring the water vapor transmission rate in the same manner as in Example 1 are shown in Table 2.

Example 7 The copolymer A obtained in Example 1 was melt-extruded to give
A 20 μm thick film was obtained.

Next, polytetrafluoroethylene (hereinafter referred to as PTFE)
After a mixture of the fine powder and the liquid lubricant described above was formed into a film, a PTFE porous body having a stable porous structure, a pore size of 2 μm, a porosity of 80% and a film thickness of 150 μm was obtained by heating and stretching.

Then, a 20 μm thick copolymer A film and the above PTFE porous body were laminated by heating and compression to obtain a composite membrane (I). The porous membrane layer of the composite membrane was impregnated with a 2 wt% ethanol solution of the copolymer A and dried to form a composite membrane (II) in which the inner wall of the pores of the porous body was coated with the acidified copolymer A. Obtained.

The membrane was hydrolyzed in the same manner as in Example 1, were converted into -SO ₃ H type, washing with water was allowed to dry.

The water vapor permeation rate of the thus-obtained membrane was measured by contacting the ion exchanger layer with water and found to be 130 Nm ³
It was / m ² · hr · atm.

Comparative Example 5 The water vapor transmission rate of the composite membrane (1) shown in Example 7 was measured in the same manner as in Example 7, and it was 75 Nm at the start of measurement for 30 minutes.
³ / m was reduced with ^{45Nm 3 / m 2 · hr ·} atm at ² · hr · atm, 120 minutes later.

Example 8 A solution of the copolymer A obtained in Example 1 in ethanolic sulfonic acid (concentration: 10% by weight) was applied to an empty polyethylene porous body having an inner diameter of 280 μm, a wall thickness of 72 μm and a porosity of 72%, and dried. A composite hollow system having 20 g of the copolymer attached per 1 m ^{2 of} membrane area was obtained.

A hollow type module (membrane effective area 50 cm ² ) was prepared by bundling 60 pieces of the hollow type with a length of 10 cm, and water was flowed inside the hollow type,
Air with a dew point of −30 ° C. was flown at 2 m / s on the outside. The water vapor transmission rate of this module was 125 Nm ³ / m ² · hr · atm.

Continuation of the front page (56) Reference JP 62-7417 (JP, A) JP 63-287530 (JP, A) JP 63-256119 (JP, A) JP 2-150640 (JP , A)

Claims (2)

[Claims] 1. A humidifying gas is brought into contact with one surface of a humidifying membrane,
In the method of humidifying a gas by bringing water into contact with the other surface, the humidifying membrane has a water absorption rate of 40 to 150% by volume, a fixed ion concentration of 0.5 to 6 N, and an ion exchange capacity of 0.6 to 2.5 meq / g resin. A humidifying method comprising an ion exchange resin layer having a film thickness of 0.1 to 300 μm and a water vapor transmission rate of 100 Nm ³ / m ² · hr · atm or more. 2. The humidifying membrane comprises an ion exchange resin layer and a pore diameter of 0.01.
The moisturizing method according to claim 1, wherein the moisturizing method is composed of a composite film having a thickness of -100 μm, a thickness of 10-500 μm, and a surface and an inner wall of which are hydrophilic.