JPH0125603B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing a hollow fiber semipermeable membrane element.

[Conventional technology]

Modules using hollow fiber semipermeable membrane elements have been used in various fields in recent years, but in order to manufacture the above elements, it is necessary to reliably seal the ends of the hollow fiber semipermeable membrane with adhesive. There is.
The present inventors thought that if a rubber substance was used as the adhesive, it would be possible to provide a novel hollow fiber semipermeable membrane element with excellent chemical resistance, and conducted repeated studies. As a result, even rubber materials that cannot be used to seal hollow fiber semipermeable membranes using the same method as conventional adhesives due to their high viscosity and poor fluidity even at high temperatures have been found to be difficult to seal. It has been discovered that sealing can be achieved by covering the outer periphery of the end with unvulcanized rubber containing a vulcanizing agent, then bonding them one by one into bundles, and vulcanizing the unvulcanized rubber while tightening the bundled coating. . However, this method requires a great deal of time to bundle the hollow fiber semipermeable membranes after being coated with unvulcanized rubber. That is,
The method of bonding rubber-coated hollow fiber semipermeable membranes one by one requires a long time of about 20 to 30 hours to manufacture one element. On the other hand, if the hollow fiber semipermeable membranes are aligned at once and both ends are fixed, the closest packing will not be achieved, and a gap will be created between the semipermeable membrane and the rubber on the open end side of the hollow fibers of the resulting element, which will reduce the yield. It is extremely low, reaching less than 10%.

[Problem that the invention seeks to solve]

The present invention provides a method for producing hollow fiber semipermeable membrane elements in a short time and with high yield.

[Means for solving problems]

The present inventors have completed the present invention as a result of repeated studies to solve the above problems. That is, in the present invention, hollow fiber semipermeable membranes are fixed substantially in parallel at regular intervals, and both ends of the hollow fiber semipermeable membranes are immersed in an unvulcanized rubber solution containing a vulcanizing agent, dried, and immersed. Form a sheet by covering the outer periphery of the hollow fiber semipermeable membrane and between the hollow fiber semipermeable membranes with unvulcanized rubber, and apply the sheet in the longitudinal direction of the hollow fiber semipermeable membrane. This is a method for manufacturing a hollow fiber semipermeable membrane element whose both ends are fixed with vulcanized rubber, which is characterized by winding it vertically into a spiral shape and vulcanizing it.

An example will be explained below with reference to the drawings.

To manufacture an element using the method of the present invention, first, as shown in FIG. The membrane is wrapped around the membrane and fixed so that the hollow fiber semipermeable membranes are substantially parallel to each other. The gap between the hollow fiber semipermeable membranes is preferably 1 mm or less. If the gap becomes large, when the hollow fiber semipermeable membrane is later wound up into a roll, the sheet hollow fiber semipermeable membrane may become uneven, and the gap between the semipermeable membranes may not be filled.

End portion 1' of hollow fiber semipermeable membrane wound around frame 2
is immersed in an unvulcanized rubber solution containing a vulcanizing agent for the length necessary for adhesion, and dried at a temperature below the vulcanization temperature of the unvulcanized rubber to form the outer periphery of the end 1' of the hollow fiber semipermeable membrane. and the gaps between them are covered with unvulcanized rubber. The opposite end is similarly covered with unvulcanized rubber, and when the hollow fiber semipermeable membrane is cut at the upper and lower inner edges of the frame 2, a sheet of hollow fiber semipermeable membrane with both ends covered with unvulcanized rubber is obtained. A similar product is obtained.

When the obtained sheet-like material 3 is wound in a spiral shape in a direction perpendicular to the length direction of the hollow fiber semipermeable membrane as shown in FIG. A bundle of permeable membranes is easily obtained.

As shown in FIG. 3, a film or sheet 5 made of the same unvulcanized rubber is wrapped around the outer periphery of the unvulcanized rubber covered portion 4 of the cylindrical bundle, and the film or sheet 5 made of the same unvulcanized rubber is wrapped in a nitrogen atmosphere or vacuum while being tightened with a band. When vulcanization is performed, a hollow fiber semipermeable membrane element having both ends fixed with vulcanized rubber is obtained.

Any pore size, thread diameter, or material can be used as the hollow fiber semipermeable membrane, but for chemical resistance, membranes made of fluorocarbon resins, olefin resins, imide resins, acrylonitrile resins, amide resins, etc. is preferred. As unvulcanized rubber, any rubber can be used as long as it is soluble in solvents and has excellent chemical resistance after vulcanization, such as vinylidene fluoride-propylene hexafluoride copolymer, vinylidene fluoride-
Fluororubbers such as propylene hexafluoride-ethylene tetrafluoride terpolymer and ethylene tetrafluoride-propylene copolymer, olefin rubbers such as EPDM and EPM, and silicone rubber are preferred, and fluororubber is particularly preferred. Any vulcanizing agent may be used as long as it can vulcanize the unvulcanized rubber, and generally organic peroxides,
Polyols and amines can be used, and an appropriate vulcanizing agent may be selected depending on the rubber used, and the amount to be blended is preferably about 1 to 10 parts.

Further, reinforcing agents, vulcanization accelerators, plasticizers, processing aids, etc. can be added as appropriate.

The hollow fiber semipermeable membrane element obtained in this way is made of polytetrafluoroethylene (hereinafter referred to as polytetrafluoroethylene).
A hollow fiber-like semipermeable membrane module with excellent drug resistance can be produced by storing the membrane in a case made of PTFE or the like and sealing it with an O-ring made of fluorocarbon rubber or the like. In this module, the adhesive part of the membrane is rubber, so if high pressure is applied, the rubber will deform.
If necessary, a pipe-shaped or rod-shaped reinforcing material 6 made of fluororesin or the like having excellent chemical resistance may be incorporated into the module, for example, into the element as shown in FIG. 4.

Example Fluororubber (Viton GF (manufactured by Dupon't)) to methyl ethyl ketone, weight ratio of Viton GF:
MEK was dissolved in a ratio of 15:100, and in this solution, 100 parts by weight of Viton GF, 2 parts by weight of Perhexa 2.5B manufactured by Nippon Oil & Fats Co., Ltd. as a vulcanizing agent, 5 parts by weight of toluaryl isocyanurate, and MT Carbon 15 Parts by weight were similarly dissolved. Hollow fiber semipermeable membrane made of ethylene-tetrafluoroethylene copolymer (outer diameter 1.2
mm, inner diameter 0.7 mm) 1 is wound around the stainless steel frame 2 so that the gap between the adjacent semipermeable membranes is 1 mm or less as shown in Fig. 1, and after immersing it in the above rubber solution to a depth of 50 mm, Dry for several minutes at °C. Repeat soaking and drying three times, and apply 0.3
A coating with a thickness of mm was applied. The opposite end was similarly coated with unvulcanized rubber. Both ends were cut at the upper and lower inner edges of the frame 2 to obtain a sheet-like hollow fiber semipermeable membrane whose both ends were covered with unvulcanized rubber. The obtained sheet material 3 was wound up in a direction perpendicular to the length direction of the hollow fiber semipermeable membrane to form a cylindrical bundle as shown in FIG. The time required to create this cylindrical bundle was approximately 1/5 of the time required by a method in which rubber-coated hollow fiber semipermeable membranes were laminated one by one and bundled.

As shown in FIG. 3, the unvulcanized rubber sheet 5
wrapped around it. Furthermore, as shown in FIG. 4, a reinforcing material 6 made of a perforated PTFE pipe was inserted as a reinforcing material for the hollow fiber semipermeable membrane. The length of the pipe was made slightly shorter than that of the cylindrical hollow fiber bundle so that it did not protrude from the end face of the semipermeable membrane. After wrapping the unvulcanized rubber sheet 5 over the pipe, PTFE
Vulcanization was performed at 180° C. for 4 hours in an oven under a nitrogen atmosphere while tightening with a mold made of plastic. The semipermeable membrane element with both end faces cut open was inserted into a housing 9 made of PTFE as shown in FIG. 5, and sealed with an O-ring 7 made of fluorocarbon rubber. After making the module hydrophilic by soaking it in ethanol for 30 minutes,
Secondary flux port 8 of the module is replaced with water.
Although a pressure of 3 Kg/cm ² was applied using air pressure, there was no leakage between the hollow fiber semipermeable membrane or between the vulcanized Viton GF and the housing. In addition, this semipermeable membrane element was immersed in 98% concentrated sulfuric acid at 80°C for 7 days and in MEK at 20°C for 7 days.
In either case, no coloration or change in appearance of the liquid was observed.

[Effects of the present invention]

According to the present invention, a hollow fiber semipermeable membrane element can be manufactured in high yield and in a short time by using a rubber substance with excellent chemical resistance as an adhesive.

[Brief explanation of drawings]

Figures 1 and 3 are a front view and a side view, respectively, illustrating a part of the process of covering the ends of the hollow fiber semipermeable membrane, and Figure 2 shows winding and alignment of the hollow fiber semipermeable membrane with the ends covered. It is a perspective view showing the process of bundling. FIG. 4 is a perspective view showing an example of the element of the present invention, and FIG. 5 is a partially cutaway view showing the element of the present invention assembled into a housing. DESCRIPTION OF SYMBOLS 1... Hollow fiber semipermeable membrane, 2... Frame, 3... Sheet-like material, 4... Covering part, 5... Unvulcanized rubber sheet, 6...
Reinforcement material, 7...O-ring, 8...Flux port, 9
…housing.

Claims (1)

[Claims] 1 Hollow fiber semipermeable membranes are fixed substantially in parallel at regular intervals, both ends of the hollow fiber semipermeable membranes are immersed in an unvulcanized rubber solution containing a vulcanizing agent, and dried to form hollow fibers at the immersed portions. A sheet-like material is formed by covering the outer periphery of the semipermeable membrane and the spaces between the hollow fiber-like semipermeable membranes with unvulcanized rubber, and the sheet-like material is glued in a direction perpendicular to the length direction of the hollow fiber-like semipermeable membrane. A method for manufacturing a hollow fiber semipermeable membrane element having both ends fixed with vulcanized rubber, which comprises winding it into a roll and vulcanizing it.