JPS62114608A - Method of producing hollow yarn-like semipermeable membrane element - Google Patents

Abstract

PURPOSE:To produce a hollow yarn-like membrane element with high yield in a short time, by fixing hollow yarn-like semipermeable membranes parallelly, coating opposite ends thereof with unvulcanized rubber, winding up a sheet-like member formed in such a manner as stated above into a rolled sheet-like form, and vulcanizing said sheet. CONSTITUTION:Hollow yarn-like semipermeable membranes 1 are wound on stainless steel frames at regular interval and fixed practically parallelly to each other. Ends of semipermeable membranes 1 are dipped into a solution of unvulcanized rubber containing vulcanizing agents and dried at a temperature below vulcanizing temperature, and outside parts of the ends and gaps between said ends are coated with unvulcanized rubber. And a sheet-like member 3 is obtained by cutting the membranes at the inner edge on the upper and lower parts of the frames. The sheet-like member 3 is wound into a rolled sheet-like form in a direction normal to the longitudinal direction of the semipermeable membranes. On the other periphery of the portion coated with unvulcanized rubber of the cylindrical bundle thus prepared a film of unvulcanized part is vulcanized in an atmosphere of nitrogen, while the part is tightened with a band. In such a manner, hollow yarn semipermeable membrane elements with both ends thereof fixed with vulcanized rubber are obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of 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 inventors believe that if a rubber substance is used as this adhesive,
We thought that it might be possible to provide a new hollow fiber semipermeable membrane element with excellent chemical resistance, and we conducted repeated studies. As a result, rubber materials, which have high viscosity and poor fluidity even at high temperatures and cannot be used to seal hollow fiber semipermeable membranes using the same methods as conventional adhesives, have been found to be able to seal hollow fiber semipermeable membranes first. 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 considerable amount of time to bundle the hollow fiber semipermeable membrane after being coated with unvulcanized rubber. That is, in the method of bonding rubber-coated hollow fiber semipermeable membranes one by one, it takes 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 formed between the semipermeable membrane and the rubber on the open end side of the hollow fibers of the resulting element, resulting in a lower yield. is extremely low, 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.
After drying, a sheet-like material is formed by covering the outer circumference of the hollow fiber-like semipermeable membrane in the immersed part and the spaces between the hollow fiber-like semipermeable membranes with unvulcanized rubber, and the sheet-like material is spread over the length of the hollow fiber-like 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 up into a spiral shape perpendicular to the direction of the winding direction and vulcanizing it.

An example will be explained below using 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 in the semipermeable membrane may not be filled.

The end 1' of the hollow fiber semipermeable membrane wound around the frame 2 is immersed in an unvulcanized rubber solution containing a vulcanizing agent for the length necessary for adhesion, and then heated to a temperature below the vulcanization temperature of the unvulcanized rubber. After drying at high temperature, the outer periphery of the ends of the hollow fiber semipermeable membrane and the gaps therebetween are coated 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, the unvulcanized rubber covered portion 4 of the cylindrical bundle
When a film or sheet 5 made of the same unvulcanized rubber is wrapped around the outer periphery and vulcanization is performed in a nitrogen atmosphere or vacuum while tightening the film with a band, a hollow fiber-like half is formed with both ends fixed with vulcanized rubber. A membrane element is obtained.

Any pore size, fiber diameter, or material can be used as the hollow fiber semipermeable membrane, but in consideration of high chemical resistance, fluororesin,
Films made of olefin resins, imide resins, acrylonitrile resins, amide resins, etc. are preferred. In addition, any unvulcanized 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-hexafluoride copolymer, etc. Fluororubber E such as fluorinated propylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-propylene copolymer, etc.
Olefin rubbers such as PDM 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 can be selected depending on the rubber used. The blending amount is usually preferably about 1 to 10 parts.

Furthermore, reinforcing agents, vulcanization accelerators, plasticizers, processing aids, and the like can be added as appropriate.

The hollow fiber semipermeable membrane element obtained in this way is
A hollow fiber semipermeable membrane module with excellent chemical resistance can be produced by storing the module in a case made of polytetrafluoroethylene (hereinafter referred to as PTFE) or the like and sealing it with an O-ring made of fluororubber or the like.

In this module, the adhesive part of the membrane is rubber, so if high pressure is applied, the rubber will deform. Therefore, if necessary, a pipe-shaped or rod-shaped reinforcing agent 6 with excellent chemical resistance such as fluororesin is installed inside the module. , for example, may be incorporated into the element as shown in FIG.

Example fluororubber (Hyton GF (manufactured by Dupon'))
to methyl ethyl ketone, weight ratio of Paiton GF:MI
EK・15:100 ratio was dissolved, and in this solution, per 100 parts by weight of Hyton CF, 2 parts by weight of NOF type Perhexa 2.5B as a vulcanizing agent, 5 parts by weight of toluaryl isocyanurate, 15 parts by weight of elbow carbon was similarly dissolved.

Hollow fiber semipermeable membrane made of ethylene-tetrafluoroethylene copolymer (outer diameter 1.2 mm, inner diameter 0.7 as) 1
was wrapped around the stainless steel frame 2 so that the gap between the adjacent semipermeable membranes was 11 cm or less, as shown in Figure 1, and immersed in the rubber solution to a depth of 50 cm, and then heated at 80°C for several minutes. Dry. The dipping and drying process was repeated three times to coat the end portion of the hollow fiber semipermeable membrane to a thickness of 0.3 mm. 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 115 minutes compared to the method of bonding rubber-coated hollow fiber semipermeable membranes one by one.
It was time.

The unvulcanized rubber sheet 5 was wrapped around the unvulcanized rubber covered portion 4 of this cylindrical hollow fiber bundle as shown in FIG.

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 slightly shorter than that of the cylindrical hollow fiber bundle so that it did not protrude from the end surface of the semipermeable membrane. After further wrapping the unvulcanized rubber sheet 5 over the pipe, , P.T.
Vulcanization was performed at 180° C. for 4 hours in an oven in a nitrogen atmosphere while tightening with an FE mold. A semipermeable membrane element with both end faces cut and opened is PT as shown in Figure 5.
It was inserted into a housing 9 made of FE and sealed with an O-ring 7 made of fluororubber. After immersing the module in ethanol for 30 minutes to make it hydrophilic, it was replaced with water and the second part of the module
Although a pneumatic pressure of 3 kg/coI was applied through the flux slot 8 on the next side, there was no leakage between the hollow fiber semipermeable membranes or between the vulcanized Piton OF and the housing. In addition, this semipermeable membrane element was soaked in 98% concentrated sulfuric acid at 80°C for 7 days.
The samples were immersed in MEK at 20°C for 7 days, respectively.
No coloration or change in appearance of the liquid was observed in either case.

[Effects of the present invention]

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

[Brief Description of the 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 a hollow fiber semipermeable membrane, and Figure 2 is a diagram showing a hollow fiber semipermeable membrane with the ends covered. It is a perspective view which shows the process of winding a semipermeable membrane and bundling it. 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. 1... hollow fiber semipermeable membrane, 2... frame, 3... sea]
- Shape 4...covered part, 5...unvulcanized rubber sheet,
6... Reinforcement material, 7... O-ring, 8... Flux port, 9... Housing. Patent applicant: Asahi Kasei Industries, Ltd. Figure 1 1'

Claims (1)

[Claims] 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, and dried to form hollow fiber semipermeable membranes at the immersed portions. A sheet-like material is formed by covering the outer periphery of the permeable membrane and the spaces between the hollow fiber-like semipermeable membranes with unvulcanized rubber, and the sheet-like material is rolled 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 whose both ends are fixed with vulcanized rubber, characterized by winding it into a shape and vulcanizing it.