JPS60257804A - Heat resistant porous polyethylene hollow yarn module - Google Patents

Abstract

PURPOSE:To enable the precise filtering of hot water, by using a porous polyethylene hollow yarn wherein an apparent m.p. is set to a specific temp. range by the irradiation of electron beam and minute voids in the wall of the hollow yarn have a crossliked structure. CONSTITUTION:Crosslinking treatment is applied to a porous polyethylene hollow yarn by an electron beam irradiation apparatus to impart heat resistance thereto. By this method, the heat resistance porous polyetylene hollow yarn, wherein an apparent m.p. is set to 150-250 deg.C by the irradiation of electron beam and minute voids in the wall of the hollow yarn are mutually connected from the inner wall surface of the hollow yarn to the outer wall surface thereof and a laminate structure is imparted, is obtained. By using this hollow yarn, a usual module is prepared.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a module using porous polyethylene hollow fibers with excellent heat resistance as a filtration membrane.

[Background technology]

BACKGROUND ART A wide variety of devices have been proposed as pure water production devices for use in fields such as medical, pharmaceutical, food, precision electronics, physical and chemical experiments, and nuclear power generation.

In other words, these pure water production devices include pure water production devices for obtaining pure water that does not contain colloidal substances or bacteria, or pure water production devices that also do not contain pyrogenic substances. There is. Distillation equipment and boiling sterilization equipment are conventional sterile water production equipment used in the medical field.

Sterilizers using ultraviolet irradiation are known, but these devices consume high energy, have high equipment costs, and do not have satisfactory sterilization efficiency.

Some of these devices can remove colloidal substances and bacteria, but cannot remove pyrogenic substances (pyrogens).On the other hand, recently, devices using reverse osmosis membranes have been developed as pure water production devices that have fewer such drawbacks. However, reverse osmosis membranes require high pressure, require large-sized equipment, and have problems such as requiring a large amount of electric power to operate.

Under these circumstances, the inventors of the present invention have solved all the drawbacks of conventional pure water production equipment, and have lowered equipment costs and energy costs for operation.
In order to develop a highly reliable precision filtration device that has a simple structure, fewer failures, and a pore size of 0.01-1μ, we
Micropores are interconnected from the inner wall surface of the hollow fiber to the outer wall surface.

We previously proposed a precision filtration module using porous polyethylene hollow fibers with a laminated structure.

However, since this module uses hollow fibers based on polyethylene, it has poor heat resistance.

Precise filtration of high-temperature water is difficult, and there has been a strong demand for the development of porous polyethylene hollow fiber modules with excellent heat resistance.

[Purpose of the invention]

An object of the present invention is to provide a heat-resistant porous polyethylene hollow fiber module capable of precision filtration of hot water at high temperatures, particularly 80°C to 100°C.

[Structure of the Invention] The present invention is characterized in that the melting point is 150°C to 25°C by electron beam irradiation.
It is a polyethylene hollow fiber kept at 0°C, and used as a porous polyethylene hollow fiber k filtration membrane having a laminated structure in which micropores in the hollow fiber wall are interconnected from the inner wall surface of the hollow fiber to the outer wall surface. The present invention relates to a heat-resistant porous polyethylene hollow fiber module.

In the polyethylene hollow fiber used in the present invention, micropores are interconnected from the inner wall surface of the hollow fiber to the outer wall surface.

It is a porous polyethylene hollow fiber having a laminated structure, and its manufacturing method is as follows:
It can be made by the method shown in et al.

A method of introducing a frame structure into such porous polyethylene hollow fibers to obtain heat-resistant porous polyethylene hollow fibers having an apparent melting point of 150°C to 250°C is to use an electron beam irradiation device, preferably at 120°C or lower. is obtained by illuminating an electron beam at 10 Mrad to 50 Mrad at a temperature of 80°C or lower. If the amount of electron beam irradiation is less than 10 Mrad, the apparent melting point will be 150° C. or less, and the heat-resistant porous polyethylene hollow fiber as the object of the present invention cannot be obtained.

Further, irradiation with an electron beam of 50 Mrad or more has an excellent effect of improving heat resistance, but the cost increase due to processing increases (which is not preferable).

To manufacture the h module using the heat-resistant porous polyethylene hollow fibers mentioned above, the entire manufacturing method of a general known module using porous hollow fibers can be applied as is. Any type of module may be used as long as the liquid or gas can be filtered from the inner wall surface to the outer wall surface.

The heat-resistant porous polyethylene hollow fiber module of the present invention is capable of precision filtration of high-temperature water of 80°C to 100°C.
The fiber morphology hardly changes even in hot water at 0°C, making it possible to remove colloidal substances, bacteria, and pyrogenic substances.In addition, compared to conventional equipment, equipment and energy costs are lower, the structure is simple, and there are fewer breakdowns (reliable). This enables precision filtration of high-temperature water.

The present invention will be explained in more detail with reference to Examples below.

Example 1 Porous polyethylene hollow fiber E HF (product name 2 manufactured by Mitsubishi Rayon Co., Ltd.) was heated at an acceleration voltage of 2 using an electron beam irradiation device.
A porous polyethylene hollow fiber having heat resistance was obtained by frame treatment by electron beam irradiation under conditions of 00 KV, 8.1 mA of electron current, and temperature of 80° C. or less.

100 heat-resistant porous polyethylene hollow fibers prepared as described above were bundled in a U-shape, the opening of the hollow fibers was hardened with resin, and the length of the resin-embedded part was 4GII.

A module with a hollow fiber effective length of 10 (up to) was created.

Using this module, 90° C. hot water was passed through the hollow fiber outer wall at a pressure of 10,100 O′ under a pressure of 38,011 iHg.

Next, we measured the effective length of the hollow fibers in this module and determined the shrinkage rate of the hollow fibers in hot water due to hot water and filtration. At the same time as the calculation, the size of the micropores in the outer wall was observed using an electron microscope, and the apparent melting point was also measured, and the results shown in Table 1 were obtained.

In addition, the performance of the hollow fiber before electron beam irradiation treatment is shown as a comparative example.

Table 1 Compared to the porous polyethylene hollow fibers before electron beam irradiation shown in Comparative Example 1 in Table 1, the porous polyethylene hollow fibers treated with electron beam irradiation shown in Examples 1 to 5 have an apparent melting point. The temperature has been greatly improved to a value of 150℃ or more, and the hot water shrinkage rate is less than 5%, and the size of the micropores in the outer wall does not change due to hot water treatment, indicating excellent heat resistance. It was confirmed that a porous polyethylene hollow fiber module having the following properties could be obtained.

Claims (1)

[Claims] (by electron beam irradiation) the apparent melting point is 1 tether r? ,~2501C
It is characterized by using a porous polyethylene hollow fiber as a filtration membrane, which has a laminated structure in which micropores in the hollow fiber wall are interconnected from the inner wall surface of the hollow fiber to the outer wall surface of the hollow fiber. hollow fiber module.