JP2000317275A - Production of hollow fiber membrane module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently form the apertures at the ends of hollow yarn membrane by cutting the ends of the hollow fiber membranes in the middle of a curing reaction of a potting resin when the hollow fiber membranes are bundled, fixed and potted by using a thermosetting resin while an opening state is maintained at one end or both ends of the hollow fiber membranes. SOLUTION: After 3500 pieces of the porous hollow fiber membranes obtained by melt hollow spinning of polyethylene are formed to a U shape, their ends are aligned and are inserted into a case made of polycarbonate forming a potting part. Next, a two-pack curing type urethane resin is injected as a potting resin into the potting resin in the module case under a centrifugal force effect in an atmosphere of about 40 deg.C and is then cured by resting for two hours. The end of the cured potting resin is sliced by a cutting to form the opening end faces of the hollow fiber membranes. After the apertures of the hollow fiber membranes are obtained, the hollow fiber membranes are rested at room temperature for four days to further cure the potting resin, by which the required hollow fiber membrane module is completed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a hollow fiber membrane module used for filtration, separation, concentration, etc. of a liquid or gas. In particular, the present invention relates to a method for manufacturing a hollow fiber membrane module in which a hollow fiber membrane is bundled, fixed, and potted using a thermosetting resin.

[0002]

2. Description of the Related Art In recent years, membrane modules have been widely used for filtering or separating liquids and gases in various industrial fields such as the medical field and the food field, and their use has been expanding to other fields. A hollow fiber membrane module using a hollow fiber membrane having a larger membrane area per unit area than a flat membrane has been used. In addition, as the performance of the membrane module expands, improvement in heat resistance, chemical resistance, mechanical strength, and the like are particularly required as performance requirements for the membrane module.

[0003] A hollow fiber membrane module is composed of a hollow fiber membrane, a module case, and a potting material. In order to form a heat-resistant or chemical-resistant hollow fiber membrane module, these components are heat-resistant and heat-resistant. It must be chemical.

[0004] Potting materials having excellent heat resistance and chemical resistance include those composed of a thermoplastic resin such as an olefin polymer or a fluororesin. However, few modules are actually available and expensive. It is. In general, a potting material made of a thermosetting adhesive is mainly used, and many of them have heat resistance and chemical resistance. Also, in hollow fiber membrane modules used in applications where heat resistance and chemical resistance are not so required,
Due to the ease of processing, an adhesive made of a thermosetting resin is often used as a potting material.

When a hollow fiber membrane is formed into a module using a thermosetting resin as a potting material, the ends of the hollow fiber membranes are stopped, and the potting resin is poured into a fixing portion of the hollow fiber membrane. In general, a method of cutting an end to obtain an opening of a hollow fiber membrane is used. In this method, conventionally, the potting resin end is cut when the curing reaction of the potting resin is almost completed. The cutting of the potting resin end is usually performed by cutting off the end with a blade and slicing the end to form a predetermined opening end face, or cutting the end while shaving using a chip saw or a saw blade to form an opening. Etc.

[0006] At the time when the cutting of the potting resin end is completed, the potting resin usually has a considerable hardness, and the method of cutting off the end by cutting it off with a blade is not suitable for cutting. Amount of shear stress is applied,
Peeling may occur at the part where the potting resin is adhered in the module case, losing the function as a membrane module.By cutting hard potting resin, the tip of the blade is easily spilled, There is also a problem that the frequency of replacement of the battery becomes high.

There is also a method of heating the cut portion at the end of the potting resin to soften the resin and then cutting the resin.
There is also the problem that the work time required for cutting becomes longer because the resin is heated each time the cutting is performed, and that when the heat resistance of the hollow fiber membrane is low, the cut surface is blocked by the melting of the hollow fiber membrane. is there.

Further, in the method of cutting while shaving using a tip saw or a saw blade, although cutting can be easily performed even with a hard resin, shavings and the like are clogged in the openings of the hollow fiber membranes and are blocked. There is also a problem that peeling easily occurs at the interface between the hollow fiber membrane and the potting resin due to the impact at the time.

For example, Japanese Patent Application Laid-Open No. Hei 6-170176 describes a method for manufacturing a hollow fiber membrane module potted with an epoxy resin. There is a possibility that separation occurs between the resin and the potting resin. Japanese Patent Application Laid-Open No. 6-55040 discloses a method in which a hollow fiber membrane is potted and fixed, and then bonded to a housing case. Peeling is also conceivable. Further, the step of bonding the housing case and the potting portion is complicated, and it takes time for bonding and fixing, so that it cannot be said that productivity is high. Further, Japanese Patent Application Laid-Open No. 6-63368 proposes a method of using an easily cutable material for a potting portion to be cut to open the end of the hollow fiber membrane.
In this case, two types of resins must be separately injected, which causes a problem in productivity.

[0010]

SUMMARY OF THE INVENTION An object of the present invention is to manufacture a hollow fiber membrane module in which the ends of a hollow fiber membrane are potted and fixed by using a thermosetting resin. An object of the present invention is to provide a method for manufacturing a hollow fiber membrane module capable of forming an opening end face efficiently without impairing the function of the hollow fiber membrane module in a cutting step for forming an opening with high productivity.

[0011]

SUMMARY OF THE INVENTION The present invention is directed to a hollow fiber membrane module in which a hollow fiber membrane is bundled, fixed and potted using a thermosetting resin while an open state is maintained at one or both ends of the hollow fiber membrane. In the method for producing a hollow fiber, cutting the hollow fiber membrane end that is bundled and fixed with the potting resin during the curing reaction of the potting resin to obtain an opening at the end of the hollow fiber membrane A method for manufacturing a membrane module.

Further, according to the present invention, after the hollow fiber membrane end which is bundled and fixed with the potting resin is cut to obtain an opening at the hollow fiber membrane end, the potting resin is forcibly heated and cured. The method for producing a hollow fiber membrane module is characterized in that the reaction is promoted.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention relates to a hollow fiber membrane module in which one end or both ends of a hollow fiber membrane is focused and fixed with a thermosetting resin potting resin, and the potting portion is cut to open the end of the hollow fiber membrane. Is a known method, except that the resin used for the potting material is cut before the curing reaction is completed.

As the potting resin in the hollow fiber membrane module of the present invention, an adhesive made of any thermosetting resin is used. For example, polyurethane-based resins, epoxy-based resins, unsaturated polyester-based resins and the like can be mentioned, and these resins can be used alone or in combination. In addition, these resins can be selected in consideration of adhesiveness to the hollow fiber membrane or the module case, heat resistance, and chemical resistance. Among them, a polyurethane resin or an epoxy resin, which can widely select curing reaction conditions, is particularly preferably used.

In the potting portion of the hollow fiber membrane module, either the potting resin may be adhered and fixed in the case or the potting resin may be exposed.

In the method of manufacturing a hollow fiber membrane module according to the present invention, the method of injecting a resin when fixing the hollow fiber membrane end portion with a resin is as follows. A method of injecting a resin, a method of injecting a resin by gravity due to a head, a method of press-fitting with a syringe or the like, and the like, and an arbitrary resin injection method is used.

When injecting the potting resin, it is necessary that the leading end portion of the hollow fiber membrane to be potted is clogged and closed by some method, and any method may be used for this clogging method. . The tip of each opening of the hollow fiber membrane may be sealed with a resin or the like, potting may be performed by crushing the tip by a method such as heat fusion, or by folding the hollow fiber membrane into a U-shape. It is possible to prevent the resin from entering the inside of the hollow fiber membrane.

After injecting a predetermined amount of thermosetting resin into a place where the hollow fiber membrane is converged and potted, the curing reaction gradually progresses due to the difference in speed depending on the resin, the fluidity is lost, and the cured product is removed. It functions as a member that closely separates the primary side and the secondary side via the membrane. This potting resin needs to be cut to form the open end face of the hollow fiber membrane.

The cutting is preferably performed at least after the resin loses its fluidity, that is, after the gelation stage. In the case of a normal thermosetting resin, the curing reaction further proceeds even after gelation, and when the curing reaction of the resin is completely completed, the potting resin is removed from the case by the impact at the time of cutting because the hardness of the resin is large. Before the resin is completely cured, the end of the potting resin is cut off before the resin is completely cured, and the curing reaction is completed after the final opening end surface is formed.

The method of cutting is not particularly limited, but a method in which a so-called guillotine-type cutter is used to cut off an edge by cutting it off with a blade, or a method in which a tip saw or a saw blade is used to cut while cutting. Any method is available.

Therefore, it is difficult for the potting resin used in the present invention to use a curing agent that completes curing in a very short time after the start of the curing reaction, but the curing is not completed until the cut is completed after gelation. It can be used without any problem as long as it is an agent or curing condition.

The hardness of the potting resin at the time of cutting is a hardness of 40 (ASTM SHORE A) of polyurethane resin.
~ 95, epoxy resin hardness (ASTM SHO
(RED) is preferably in the range of 40 to 90, and the hardness when the curing reaction is finally completed is the hardness (A) of the polyurethane resin.
STM SHORE A) is preferably in the range of 60 to 100, and epoxy resin is preferably in the range of 50 to 100 in hardness (ASTM SHORE D). As described above, the hardness of the potting resin at the time of completion of the curing reaction is higher than that at the time of cutting.
At the time of cutting, other mechanical properties in the cured product are not particularly limited numerically, after cutting,
Strength and elastic modulus will be improved.

The curing of the potting resin used in the present invention requires several hours or more to complete the curing reaction, and the conditions for curing by a two-stage or multi-stage curing reaction depending on the temperature conditions are the easy-to-use curing. It can be said that it is a condition.

For example, under curing conditions in which the curing reaction can be divided into two stages, from the time of injection of the resin to gelation, the reaction is performed at a relatively low temperature (for example, normal temperature), and after gelation, the potting resin end is cut. Then, an opening end face is formed. At this time, if the temperature is kept low, the curing reaction does not proceed any further, but thereafter, there is a method in which the potting portion is heated or heated to accelerate the curing reaction and improve the physical properties of the cured resin. After this opening end face is formed, the method of heating or heating to accelerate the curing reaction is not only a curing reaction divided into two steps or a multi-step, but also a curing reaction in which the curing reaction progresses with time even at a low temperature to reach final physical properties. Even in the case of conditions, cut in the middle of the curing reaction to form an open end face, and then
The curing reaction can be accelerated by heating or heating.

When the potting portion is forcibly heated after the formation of the opening end face, the heating temperature is not particularly limited.
It is preferable to heat in a high temperature atmosphere in the range of 00 ° C.

In the present invention, the point at which there is substantially no change in the hardness, strength, elastic modulus, etc. of the surface of the cured resin product is regarded as the end of the curing reaction even if measures are taken to advance the curing reaction thereafter. For example, when left at room temperature for 24 hours, when forcedly heated, it is left at the heated temperature for 8 hours, and when the value of hardness no longer increases, it is considered that the curing reaction has been completed.

Examples of the material of the hollow fiber membrane constituting the hollow fiber membrane module of the present invention include polyolefins such as polyethylene, polypropylene and poly (4-methylpentene-1), polysulfone, polyarylsulfone, polyethersulfone and polyamide. And the like. The hollow fiber membrane may be a porous membrane or a non-porous membrane, and can be freely selected depending on the application.

The module case used in the present invention may be of any type, but preferably has heat resistance and solvent resistance, and is preferably made of resin rather than metal in view of workability and cost. preferable. As the heat resistant resin, a polycarbonate resin, an acrylic resin, a polyolefin resin, a polysulfone resin, a polyphenylene oxide resin, a polyacetal resin, and the like can be selected.For applications such as solvent filtration and pervaporation, a polyolefin material is preferable. .

The interior of the module case may be surface-treated in order to improve the adhesion between the potting material and the module case. For example, in the case of a polypropylene module case, plasma discharge treatment, corona discharge treatment, flame Treatment, ozone treatment, chromium mixed acid treatment, n
-Hexane treatment, primer treatment, roughening treatment, etc. are performed alone or in combination.

[0030]

The present invention will be described below in more detail with reference to examples.

Example 1 A porous hollow fiber membrane (outer diameter 380 μm, inner diameter 270 μm) having an average pore diameter of 0.1 μm obtained by melt hollow spinning polyethylene was used as the hollow fiber membrane. 3500 hollow fiber membranes are formed into a U-shape, the ends thereof are aligned, and inserted into a polycarbonate case forming a potting portion. As a potting resin, Coronate 4403 (manufactured by Nippon Polyurethane Co., Ltd .; urethane-based adhesive base material; Under a 40 ° C. atmosphere, 60 g of a two-part curable urethane resin obtained by blending 62 parts by weight of Nipporan 4276 (trade name) and 38 parts by weight of Nipporan 4276 (manufactured by Nippon Polyurethane Co., Ltd .; urethane-based adhesive curing agent) was added. Under a centrifugal force of 44G, the potting portion in the module case is injected over 3 hours (gelation in 3 hours), and then left at room temperature for 2 hours to harden. It was.

The end of the cured potting resin was sliced with a guillotine cutter to form an open end face of the hollow fiber membrane. After obtaining the opening of the hollow fiber membrane in this way, 4
The potting resin was further cured by leaving it at room temperature for a day to obtain a hollow fiber membrane module. Separately, a two-part curable urethane resin blended under the same conditions as those used in the present example was placed under the same temperature as in the present example, and the time elapsed corresponding to the time when cutting was performed The hardness (ASTM SHORE A) of the subsequent potting resin was 72, and the tensile strength was 5.1 MPa. Then add this at room temperature 4
Hardness of potting resin (AS
TM SHORE A) is 93, tensile strength is 17.6M
At Pa, there was no change in these properties thereafter.

The manufactured hollow fiber membrane module was a membrane module having no leakage without peeling of the potting resin from the inner surface of the case or peeling of the hollow fiber membrane from the potting resin.

Example 2 A hollow fiber having a three-layered membrane structure in which a porous layer of polyethylene and a homogeneous layer of segmented polyurethane were used as the hollow fiber membrane, and a homogeneous layer obtained by hollow spinning was sandwiched between the porous layers. Membrane (outside diameter 280 μm, inside diameter 200 μm)
20500 hollow fiber membranes having a length of about 28 cm are bundled, and both ends are aligned and inserted into a cylindrical module case made of modified polyphenylene oxide resin, and arranged.
After sealing the open ends of both ends of the hollow fiber membrane bundle by heat fusion, epicoat 828 (bisphenol type epoxy resin, trade name, manufactured by Yuka Shell Co., Ltd.) is applied to both ends of the hollow fiber membrane bundle.
26.4 parts by weight, 44.0 parts by weight of Epicron TSR-243 (made by Dainippon Ink and Chemicals, Inc., urethane-modified epoxy resin, trade name), ERISYS GE-60 (BT
R Japan, sorbitol polyglycidyl ether,
8.8 parts by weight, PACM (manufactured by BTR Japan,
Curing agent: epoxy resin 75 containing 20.8 parts by weight of bis (4-aminocyclohexyl) methane (trade name)
g as a potting resin under an atmosphere of 40 ° C.
The mixture was injected into the potting portion in the module case over 80 minutes under the action of the centrifugal force of G (gelled in 70 minutes), and then left in a dryer at 65 ° C. for 30 minutes to cure.

The end of the cured potting resin was sliced with a guillotine cutter to form an open end face of the hollow fiber membrane. After the opening of the hollow fiber membrane was obtained, the curing reaction was promoted at 80 ° C. for 6 hours to completely cure, thereby obtaining a hollow fiber membrane module. The potting resin was separately adjusted in the same manner as in Example 1, and the hardness (ASTM SHORE D) of the potting resin after elapse of time corresponding to the time of cutting was 64, and the flexural modulus was 920 MPa. Similarly, the potting resin completely cured by further promoting the curing reaction at 80 ° C. for 6 hours had a hardness (ASTM SHORED) of 89 and a flexural modulus of 1790 MPa, and thereafter there was no change in these physical properties.

Fifty hollow fiber membrane modules were produced by the above-mentioned method, and a hollow fiber membrane module having no leak was produced without peeling of the potting resin and the case or peeling of the hollow fiber membrane and the potting resin in all of the modules.

[Comparative Example 1]
A hollow fiber membrane module was prepared in the same manner as in Example 2 except that the curing was performed at 5 ° C. for 30 minutes and at 80 ° C. for 6 hours.
Leakage occurred due to peeling of the potting resin and the inner surface of the module case in 28 of the thus produced products.

[0038]

According to the present invention, since the potting resin end is cut to form the open end face of the hollow fiber membrane before the potting resin curing reaction is completed, the shear stress at the time of cutting can be reduced. As a result, there is no peeling of the module case and the potting resin and no peeling of the hollow fiber membrane and the potting resin, and a hollow fiber membrane module free from leaks can be produced efficiently (with good yield) in a simple process.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Osamu Kato 4-160 Sunadabashi, Higashi-ku, Nagoya-shi, Aichi F-term (reference) 4D006 GA02 HA02 HA03 JA13C JA25C JB05 JB06 JB08 MA01 MA06 MA33 MC22X MC23 MC53X MC54 MC62 MC63 PA01 PA02

Claims (6)

[Claims] In a method for manufacturing a hollow fiber membrane module, a hollow fiber membrane is bundled, fixed and potted using a thermosetting resin while maintaining an open state at one end or both ends of the hollow fiber membrane. A method for producing a hollow fiber membrane module, comprising cutting an end of a hollow fiber membrane that is bundled and fixed with a potting resin during a curing reaction to obtain an opening at the end of the hollow fiber membrane. 2. An end portion of the hollow fiber membrane which is bundled and fixed with a potting resin is cut to obtain an opening at the end portion of the hollow fiber membrane, and then the potting resin is forcibly heated to accelerate the curing reaction. The method for manufacturing a hollow fiber membrane module according to claim 1, wherein 3. The method for producing a hollow fiber membrane module according to claim 1, wherein the thermosetting resin is a polyurethane resin. 4. The method for producing a hollow fiber membrane module according to claim 1, wherein the thermosetting resin is an epoxy resin. 5. The hardness of the potting resin at the time of cutting is AST.
4. The hollow fiber according to claim 3, wherein the M SHORE A hardness is in the range of 40 to 95, and the hardness at the time of completing the curing reaction of the potting resin after cutting is higher than the hardness at the time of cutting. Manufacturing method of membrane module. 6. The hardness of the potting resin at the time of cutting is AST.
The hollow fiber according to claim 4, wherein the M SHORE D hardness is in the range of 40 to 90, and the hardness at the time of completing the curing reaction of the potting resin after cutting is higher than the hardness at the time of cutting. Manufacturing method of membrane module.