JPH06114241A - Production of fluid separation membrane module - Google Patents

Abstract

PURPOSE:To provide a method for safely and easily producing a separation membrane module. CONSTITUTION:This fluid separation membrane module is a fluorine-base porous separation membrane module having such structure that at least a part of fine pores in the fluorine-base porous separation membrane is impregnated with a solidified potting material in the potting part of the module. This module is produced by treating the surface of the fluorine-base porous separation membrane with a surfactant and then bonding plural numbers of fluorine-base porous separation membranes with a potting agent having viscosity between in 100 to 1000 cp.

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 fluid separation membrane module using a fluorine-based porous separation membrane.

[0002]

2. Description of the Related Art Fluorine-based porous separation membranes not only have excellent heat resistance and chemical resistance, but also have excellent stain resistance, elution and oxygen permeability. Taking advantage of its characteristics, it is attempted to be put to practical use in water treatment, gas separation, chemical filtration, and bacterial cell separation in the bio industry. Fluorine-based porous separation membranes are difficult to put into practical use in the state of the membrane itself,
It is necessary to put the membrane into an appropriate shape and put it into practical use in the form of a sealed membrane separation module. However, in general, the fluorine-based porous separation membrane has extremely poor adhesiveness, and since the membrane cannot be well adhered and sealed by an adhesive method using an ordinary adhesive, these fluorine-based porous separation membranes are sealed. Various studies have been conducted on the method.

At present, the most commonly used method is as follows.
Fluorine-based porous separation membranes are bonded by heat-sealing with fluororesin of the same system by heat-sealing method, and fluorine atoms on the membrane surface are treated by chemical etching at the planned adhesion part of the fluorine-based porous separation membranes. There is a method such as a chemical etching method for improving the adhesiveness by pulling out the adhesive, and a method for improving the adhesiveness by performing corona discharge or plasma treatment on a planned adhesion portion of the fluorine-based porous separation membrane prior to the adhesion. However, even if an attempt is made to manufacture a fluorine-based porous separation hollow fiber separation membrane module by an adhesion method by heat fusion, it is not easy to successfully fill the fluorine resin for heat fusion between the membranes. In addition, the chemical etching method has problems such as discoloration of the membrane surface and difficulty in handling, and it is difficult to efficiently and reliably treat a bundle of thousands of hollow fiber membranes by the corona discharge or plasma treatment method. It was difficult to solve the problem, and the best solution was difficult.

As a means for improving these problems and firmly adhering and fixing the hollow fiber membrane bundle with an adhesive to produce a good hollow fiber membrane module, JP-A-3-106422 is known.
Proposes a method in which the micropores open on the surface of the hollow fiber membrane are used to treat the membrane surface with an organic solvent and then apply an adhesive to impregnate and solidify the adhesive in the micropores on the membrane surface. ing.

[0005]

However, the method of applying an adhesive after treating the hollow fiber membrane with an organic solvent as described in Japanese Patent Laid-Open No. 3-106422 has a remarkable adhesive effect as compared with the prior art. However, some drawbacks have been identified. That is, when, for example, ethanol is used as the organic solvent, it is not easy to optimize the time for the ethanol immersion treatment, and the evaporation rate of ethanol changes due to changes in the outside air temperature due to seasonal variations, and the anchor effect of the organic solvent Inhomogeneous states may be seen. In addition, residual components of ethanol may evaporate during curing of the adhesive and deprive the adhesive of the heat of curing to cause defective curing. As described above, the method for producing a fluorine-based hollow fiber membrane module involving the treatment with an organic solvent described in JP-A-3-106422 is an epoch-making means, but is not the best means for the above reasons. It was

An object of the present invention is to solve the above-mentioned drawbacks of the prior art and to provide a reliable and excellent workability of a fluorine-based porous separation membrane, particularly a fluid separation membrane module using a fluorine-based porous hollow fiber separation membrane. Providing a manufacturing method.

[0007]

According to the present invention, the potting agent is permeated and solidified in at least a part of the micropores in the fluorine-based porous separation membrane in the potting portion of the fluorine-based porous separation membrane module. And a potting agent having a viscosity of 100 cp or more and 10000 cp or less after treating the surface of the fluorine-based porous separation membrane with a surfactant. This is achieved by manufacturing a fluid separation membrane module by a method for manufacturing a fluid separation membrane module, which is characterized in that it is adhered by.

That is, since the fluorine-based porous separation membrane is a fluororesin whose adhesiveness is inferior to that of the membrane material, even if it is treated with a surfactant, it should be adhered with a general adhesive such as an epoxy adhesive. Was considered difficult.

However, the fluorine-based porous separation membrane has innumerable fine pores having a diameter of 0.01 to 0.5 μm. By treating the membrane surface with an appropriate surfactant, the fine pores can be treated. The inner surface is temporarily rendered hydrophilic or lipophilic. In this state, the viscosity of 100 disclosed in the present invention is obtained.
When a potting agent of cp or more and 10000 cp or less is applied to the surface of the membrane, the penetration of the potting agent into the inside of the fine pores is remarkably improved, and the potting agent is hardened in a state of being rooted inside the membrane (anchor effect). It was found that the porous separation membrane was firmly fixed (bonded) with an epoxy adhesive. At this time, even if the adhesive is applied to the film surface without performing the operation of applying and filling a surfactant in the fine pores, the adhesive is not hydrophobic because the fluororesin itself is hydrophobic. Therefore, the fluorine-based porous separation membrane is not adhered.

Membrane materials for the fluorine-based porous separation membrane of the present invention include polytetrafluoroethylene, polyvinylidene fluoride, tetrafluoroethylene-ethylene copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, and tetrafluoroethylene. Ethylene-perfluoroalkyl vinyl ether copolymer, polychlorotrifluoroethylene, and the like, as long as it is possible to form a fluorine-based porous separation membrane, the kind is not particularly limited, but preferably, particularly in the usual method Polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkylvinylether copolymer (PFA), and tetrafluoroethylene-hexafluoropropylene copolymer (FEP), which are difficult to adhere, are suitable.

The structure of the fluorine-based porous separation membrane is not particularly limited, but a membrane having a sponge structure having innumerable fine pores as seen in precision filtration membranes and ultrafiltration membranes penetrates the potting agent. It is particularly suitable because of its high effect. Regarding the state of distribution of the micropores, it may be a uniform distribution or a film in which the pore sizes of the micropores are different and the distribution is asymmetric.
That is, the potting agent permeates into the micropores of the membrane by treating the fluorine-based porous separation membrane by the method of the present invention,
It is firmly adhered by the above-mentioned so-called anchor effect.

The surfactant used in the present invention is not particularly limited as long as it temporarily hydrophilizes or makes lipophilic the inner surfaces of the fine pores of the fluorine-based porous separation membrane, but preferably 0.1% by weight. Surface tension of aqueous solution is 30 dynes / cm
One or more surfactants selected from those having a temperature of (25 ° C.) or lower are suitable. 25 dyn depending on the membrane material
es / cm (25 ° C) or less is preferable, and further 20 dynes
/ cm (25 ° C) or less is preferable. The surfactant is not particularly limited as long as it does not inhibit the adhesion or the like due to remaining components that inhibit the adhesion or forming an abnormally bulky group. The surfactant may be selected from anionic, cationic, amphoteric or nonionic hydrocarbon-based or fluorocarbon-based surfactants, and may be used alone or in combination. Among these, carbon fluoride based surfactants are particularly preferable.

The treatment method may be a method of immersing the entire separation membrane or a portion to be adhered in a surfactant, and may be a batch method or a continuous method during film formation. Further, the surfactant may be used by dissolving it in a solvent such as water or alcohol.

The dipping time may be any time required for the surfactant solution to penetrate into the film, and usually 1 minute or more and 30 minutes or less is sufficient. The immersion temperature is preferably 0 to 30 ° C.
In addition, after applying the surfactant, it is preferable to dry it at room temperature or an appropriate temperature to keep it in a dry state in order to improve workability of the potting agent application work.

The potting agent used has a viscosity of 100c.
It is necessary to be p or more and 10000 cp or less, and more preferably 100 cp or more and 5000 cp or less. If the viscosity is less than 100 cp, the flow becomes so easy that handling becomes difficult, and if it exceeds 10,000 cp, it does not sufficiently penetrate into the fine pores, which is not preferable.

As the potting agent, for example, epoxy type and urethane type are preferably used, and more preferably, epoxy adhesives relatively excellent in strength and heat resistance are desirable. The types of epoxy adhesives include
Epi-bis type, alicyclic type, long-chain aliphatic type, novolak type,
Brominated epoxy resins and heterocyclic systems are preferred. As the curing agent, acid anhydride type, aromatic amine type, aliphatic amine type and the like are used. The initial viscosity of the potting agent may be any viscosity that allows the potting agent to penetrate into the fine pores of the membrane, and it is particularly preferably in the range of 2000 to 5000 cp. When the separation membrane is a hollow fiber, if the curing time becomes too long, the potting agent that has permeated through the micropores on the outer surface of the membrane may reach the hollow interior of the hollow fiber membrane, causing the clogging of the hollow fiber membrane. The curing time of the potting agent varies depending on the shape of the separation membrane to be adhered, the pore size, the distribution, etc., but is usually 2 to 5 hours.

In the fluid separation membrane module of the present invention, it is necessary that the potting agent is permeated and solidified into the fine pores in the membrane of the fluorine-based separation membrane in the potting end plate portion, but preferably the fluorine is used. 1% or more of the in-membrane micropores of the system separation membrane is more preferably 5
% Or more is preferably filled with the potting agent.

Here, the fact that 1% or more of the micropores in the film is filled with the potting agent means that 1% or more of the volume of all the micropores in the potting portion is filled with the potting agent.

[0019]

【Example】

Example 1 An average pore diameter of 0.03 to 0 obtained by adding sodium alginate and barium sulfate to a polytetrafluoroethylene aqueous dispersion (D-2 manufactured by Daikin Co., Ltd.), performing dry and wet spinning, and then treating with concentrated sulfuric acid. The end of the hollow fiber of the dried polytetrafluoroethylene porous hollow fiber membrane having fine pores of .05 μm is bonded by sealing with “Cemedine C” (manufactured by Cemedine Co., Ltd.) so that the potting agent does not cause clogging. . Next, a surfactant (Sumitomo 3M FC-129, surface tension of a 0.1 wt% aqueous solution (25
℃): 17 dynes / cm) about 10% in 0.1% by weight aqueous solution
Soak for 1 minute and dry in air for 2 hours to keep the film surface dry. Next, insert this yarn bundle into the module container and tighten the mounting jig. Securely fix the yarn bundle and container. Next, the epoxy adhesive "Araldite CY23"
0 / HY956 (manufactured by Ciba-Geigy Japan, compounding ratio 10
0: 9) ”is mixed and transferred to a syringe and poured into a container to cure the potting agent. After curing, the adhesive is cut with a rotary blade cutter to form a hollow fiber module, and then the cutting is performed. When observing the surface with an optical microscope,
The fluorine-based hollow fiber membrane and the potting agent were firmly adhered to each other, and neither peeling nor deformation was observed.

Next, the potting end plate portion of the hollow fiber membrane of the same module was disassembled to include the porous hollow fiber membrane portion 1
A small sample of 0 mm square and 35 mm long potting part was manufactured, the sample was frozen with liquid nitrogen, and then cut with a knife so that the cross section of the hollow fiber membrane appeared, and the cut surface was a scanning electron with a magnification of 30,000 times. Observation with a microscope was performed to confirm the penetration state of the potting agent. As a result, it was confirmed that about 3% of the micropores in the membrane in the cross section of the hollow fiber membrane were filled with the potting agent.

Comparative Example 1 A hollow fiber membrane module was produced by adhering under the same conditions and methods as in Example 1 except that a surfactant was not used, and when observed in the same manner, a potting agent and a hollow fiber membrane were obtained. It was confirmed that the hollow fiber membrane was peeled off and the hollow fiber membrane was largely deformed, and it was confirmed that the interface between the two was not adhered.
In addition, in Example 1. A potting part sample was manufactured by the same method as above, and the cross section was observed using a scanning electron microscope under the same conditions.As a result, the potting agent formed fine pores in the film in both the peeled and non-peeled parts. It was confirmed that it had not penetrated.

[0022]

According to the present invention, a fluid separation membrane module in which a plurality of fluorine-based porous separation membranes are firmly bonded with a potting agent can be manufactured by a simple and safe method.

Claims (4)

[Claims] 1. A fluid separation membrane module, wherein an adhesive is permeated and solidified into at least a part of micropores in the membrane of the fluorine-based porous separation membrane in the potting portion of the fluorine-based porous separation membrane module. The manufacturing method of
A method for producing a fluid separation membrane module, which comprises treating the surface of a fluorine-based porous separation membrane with a surfactant, and then bonding the plurality of fluorine-based porous separation membranes with a potting agent having a viscosity of 100 cp or more and 10000 cp or less. . 2. The surface tension of a 0.1% by weight aqueous solution is 30 dyne.
The method for producing a fluid separation membrane module according to claim 1, wherein a surfactant having a s / cm (25 ° C.) or less is used. 3. The method for producing a fluid separation membrane module according to claim 1, wherein the separation membrane is a flat membrane. 4. The method for producing a fluid separation membrane module according to claim 1, wherein the separation membrane is a hollow fiber membrane.