JP3282334B2 - Method for hydrophilizing polysulfone hollow fiber membrane - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for hydrophilizing a polysulfone hollow fiber membrane. More specifically, the present invention relates to a method for heat-treating a polysulfone hollow fiber membrane which enables permanent hydrophilicization.

[0002]

2. Description of the Related Art When a hydrophilic hollow fiber membrane is produced from hydrophobic polysulfone, hydrophilicity is imparted by mixing a hydrophilic polymer substance such as polyvinylpyrrolidone. However, when water is passed through the hollow fiber membrane obtained by such a method, the hydrophilic polymer substance is gradually eluted, and the hydrophilicity of the hollow fiber membrane is eventually lost.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a polysulfone hollow fiber membrane to which polyvinylpyrrolidone which is a hydrophilic polymer substance is added, and a method for heat-treating the polysulfone hollow fiber membrane in which permanent hydrophilicity is imparted thereto. Is to provide.

[0004]

SUMMARY OF THE INVENTION The object of the present invention is as follows.
After dry-wet spinning of a hollow fiber membrane from a polysulfone spinning stock solution containing about 0.1 to 10% by weight of polyvinylpyrrolidone,
This is achieved by performing pressure heating in water at 110 ° C. or higher.

[0005] Polyvinylpyrrolidone added as a hydrophilic polymer substance has a molecular weight of about 10,000 (K-15) to 120.
0000 (K-90) is used in such a ratio that it occupies about 0.1 to 10% by weight, preferably about 0.1 to 6% by weight in the spinning dope.

The spinning solution to which such polyvinylpyrrolidone is added is about 10 to 30% by weight, preferably about 13 to 20% by weight.
% By weight of polysulfone in dimethylformamide, diethylformamide, dimethylacetamide, diethylacetamide, dimethylsulfoxide,
It is used by dissolving it in an aprotic polar solvent such as N-methyl-2-pyrrolidone and triethyl phosphate.

[0007] The spinning dope formed from polysulfone, polyvinylpyrrolidone and an aprotic polar solvent, etc., may have a molecular weight of approximately
Polyethylene glycol of about 400 to 6000, about 1 to
20% by weight, preferably about 13 to 20% by weight can be added.

[0008] The formation of a hollow fiber membrane using such a spinning solution is as follows.
It is extruded from a double annular nozzle, run idle, and then gelled in an aqueous coagulation bath generally using water.

The polysulfone hollow fiber membrane gelled in an aqueous coagulation bath is subjected to a heat treatment in water at about 110 ° C. or higher, preferably about 121 ° C. Since this heat treatment is naturally performed under a pressurized condition, it is performed using an autoclave or the like for about 5 minutes or more, preferably for about 15 to 60 minutes, and at the same time, washing is performed at the same time.

[0010]

The polysulfone hollow fiber membrane to which polyvinylpyrrolidone is added as a hydrophilic polymer substance is subjected to a high-temperature heat treatment in water, so that the elution of the hydrophilic polymer substance is small, and thus a permanent hydrophilic property is imparted. The obtained polysulfone hollow fiber membrane is obtained.

[0011]

Next, the present invention will be described with reference to examples.

Example 1 Polysulfone 14 parts by weight Polyethylene glycol (molecular weight 600) 14 << polyvinylpyrrolidone (molecular weight 40000) 1 << dimethylformamide 71 >> A spinning stock solution comprising the above components was extruded from a double annular nozzle, and was extruded from a water coagulation bath. By dry-wet spinning method to gel,
A polysulfone hollow fiber membrane was manufactured.

At this time, A: a hollow fiber membrane gelled in a water coagulation bath B: a hollow fiber membrane gelled in a water coagulation bath and then washed with water for about 2 hours C: after a gelation in a water coagulation bath The hollow fiber membrane was placed in an autoclave as it was, and treated in water at 121 ° C. for 20 minutes. D: The hollow fiber membrane obtained by washing the hollow fiber membrane of the above C for about 2 hours was dried once and then wetted once with ethanol. When the percentage of the pure water permeability coefficient of the dry hollow fiber membrane relative to the pure water permeability coefficient when replaced with pure water is measured as the degree of hydrophilicity, the following results are obtained. It can be seen that permanent hydrophilization is achieved.

Example 2 In Example 1, the amount of polyvinylpyrrolidone was changed to 0.5 parts by weight. At this time, E: hollow fiber membrane gelled in a water coagulation bath F: gelled in a water coagulation bath, then placed in an autoclave as it is and treated in water at 121 ° C. for 20 minutes G: F above The following results were obtained by measuring the degree of hydrophilicity of the hollow fiber membrane obtained by further washing the hollow fiber membrane with water for 2 hours.

Comparative Example In Example 1, no polyvinylpyrrolidone was used. At that time, H: hollow fiber membrane gelled in a water coagulation bath I: gelled in a water coagulation bath, then put directly into an autoclave and treated in water at 121 ° C. for 20 minutes to obtain a hydrophilic fiber When the degree was measured, the following results were obtained.

Claims (1)

(57) [Claims] 1. A After dry-wet spinning of hollow fiber membrane from 0.1 to 10 wt% of polyvinylpyrrolidone polysulfone spinning solution was added, polysulfone hollow fiber membrane, characterized by pressurizing and heating treatment in water above 110 ° C. Method for hydrophilization.