Liquid purification or separation – Filter – Material
Patent
1981-06-15
1983-08-16
Spear, Jr., Frank A.
Liquid purification or separation
Filter
Material
B01D 3100
Patent
active
043990355
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
This invention relates to a screen type polyvinylidene fluoride type resin hollow filament microfilter with a double layer structure of skin layers and a support layer. More particularly, the present invention is concerned with a high-performance screen type polyvinylidene fluoride type resin hollow filament microfilter which is capable of separating substances through thin skin layers present on the surfaces of the hollow filament, said thin skin layers comprising pores with a sharp pore diameter distribution, and which has excellent properties such as a high selectivity in permeation, a high permeability, a high porosity, a resistance to repeated drying operations, and is excellent in mechanical strength, chemical resistance, heat resistance, microorganism resistance and inertness to a living body.
DESCRIPTION OF THE PRIOR ART
Recently, using various kinds of materials, there are produced high polymer porous membranes having pore diameters varied in a wide range, for example, reverse osmosis membrane, ultrafiltration membrane, microfilter and the like. Such porous membranes made of these various kinds of materials, due to their excellent properties such as a high permeation selectivity (cut-off characteristics) and a high permeability, have been used in a wide variety of applications, for example; (1) production of plain water from salt water, desaltation of sea water, removal of alkalis, acids and the like from the industrial wastes, (2) recovery of the degreasing solution used in the pretreatment for plating, electrodeposition coating solution and the like, paper-pulp waste water treatment, oil-water separation, oil-emulsion separation, and the like, (3) separation and purification of fermentation products, condensation of fruit juice and vegetable juice, soybean treatment, and separation and purification of products in the food industry such as sugar manufacture and the like, and (4) medical applications such as a filtration type artificial kidney, a microfilter for separating various microorganisms, separation and purification of pharmaceutical products, and the like.
The term "microfilter" is used herein to mean a separator membrane having pores of 0.05 to 1.0 .mu.m in average pore diameter (2r) as is generally defined for its meaning. Such a microfilter is capable of passing therethrough proteins having a molecular weight ranging from thousands to hundreds of thousands, but does not pass therethrough substances with molecular weights larger than the above-mentioned, such as yeast (of 2-4 .mu.m), fungi (of 1-2 .mu.m), and causative viruses of diseases (of molecular weight: 2,400,000). Albumin contained in body fluids can pass through it while fungi cannot pass. Emulsion particles cannot pass through it while colloidal particles can pass. Microfilters have been used for separating emulsions, yeasts, fungi and the like. According to the recent remarkable development of applications, the need of use of microfilters under rigorous conditions has been rapidly increased. Such uses include (1) treatment of strong alkali or acid solutions, (2) treatment under high temperatures, (3) treatment of organic solvents, heat sterilization at 121.degree. C. and 1.5 atm in an autoclave, sterilization with hypochlorous acid, and the like. It has, therefore, a strong desire to develop a high-performance microfilter having acid resistance, alkali resistance, heat resistance, solvent resistance and chemicals resistance so that it can withstand the above-mentioned treatments under the rigorous conditions.
With respect to porous membranes produced in the recent development of membrane-producing techniques and the chemicals resistance of such membranes, attention may be called to, for example, a cellulose acetate porous membrane as disclosed in U.S. Pat. No. 3,883,626, which is produced from a solvent and non-solvent system comprising cellulose diacetate, acetone, methanol, cyclohexanol and CaCl.sub.2.2H.sub.2 O. Such a cellulose acetate porous membrane obtained from the above-mentioned system not
REFERENCES:
patent: 3423491 (1969-01-01), McLain et al.
patent: 3615024 (1971-10-01), Michaels
patent: 3642668 (1972-02-01), Bailey et al.
patent: 3852224 (1974-12-01), Bridgeford
patent: 3975478 (1976-08-01), Leonard
patent: 4181694 (1980-01-01), Hashino et al.
patent: 4203847 (1980-05-01), Grandine
patent: 4203848 (1980-05-01), Grandine
patent: 4268279 (1981-05-01), Shindo et al.
Nohmi Takashi
Yamada Takao
Asahi Kasei Kogyo Kabushiki Kaisha
Spear, Jr. Frank A.
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