JPH0331493B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a permeable membrane with high oxygen permeability.

Membranes with high oxygen gas permeability are useful in artificial gills for humans to directly take in oxygen from water when working underwater, in artificial lungs used during surgery, and in oxygen separation membranes with high oxygen permeability.

The necessary conditions for a membrane with high oxygen gas permeability include high oxygen permeability, sufficient mechanical strength, good moldability, and sufficient chemical resistance depending on the application. However, a polymer membrane that satisfies these requirements at the same time has not been realized.

For example, silicone rubber is a typical conventional membrane with high oxygen gas permeability, but it has the drawback of poor moldability.

A method of introducing a fluorine compound into a polymer membrane already exists as a method for improving oxygen permeability. That is, a method has been proposed (Japanese Unexamined Patent Publication No. 51-98684) using a polymer membrane containing a fluoroacylated ethyl cellulose derivative as a gas permeable membrane for a blood oxygenator. However, when compared to non-fluorinated ethyl cellulose, its oxygen gas permeability is approximately
The increase is only 1.9 to 3.0 times, which is insufficient.

As a result of intensive research on membranes with high oxygen gas permeability, the present inventors discovered that a polymer membrane with a specific fluorine-containing substituent could be suitable for the purpose, and based on this knowledge, the present inventors The invention was completed.

That is, the present invention provides a highly oxygen gas permeable membrane characterized by being made of a polymer derivative containing a perfluoroether group represented by the following general formula as a side chain substituent. The polymer into which the perfluoroether substituent is introduced is a polymer having a functional group such as a hydroxyl group, an amino group, or an amide group that reacts with a fluorine-based acylating agent such as an acid fluoride containing the perfluoroether group. For example,
Examples include cellulose polymers, chitosan polymers, polyamides, and vinyl alcohol polymers. Examples of cellulose polymers include ethyl cellulose, methyl cellulose, hydroxyethyl cellulose, ethyl hydroxyethyl cellulose, carboxymethyl cellulose and its salts, cellulose nitrate, cellulose acetate, and mixed esters of cellulose. Examples of chitosan-based polymers include ethyl chitosan, methyl chitosan, acetic chitosan,
Examples include carboxymethyl chitosan and its salts, hydroxyethyl chitosan, and the like. Polyamides include 6-6 nylon, 6 nylon, 11 nylon,
Examples include nylon 6-10, isophthalic acid chloride and m-phenylenediamine copolymer, and m-xylenediamine and adipic acid copolymer. Examples of the vinyl alcohol polymer include polyvinyl alcohol, ethylene-vinyl alcohol copolymer, and partially saponified polyvinyl acetate.

As mentioned above, the functional groups that react with a fluorine-based acylating agent such as an acid fluoride contained in the polymer used in the present invention include a hydroxyl group, an amino group, or an amide group. In order to achieve the intended purpose,
It is necessary that the amount of reacting nuclear functional groups (amino groups, hydroxyl amide groups, etc.) be at least about 10% by weight of the polymer. If it is less than 10% by weight on average, the effect of the fluorine-containing substituent group will not be sufficiently exhibited, and the increase in transmittance ratio and transmittance will be small.

Examples of the fluorine-based acylating agent to be reacted with the polymer used in the present invention include: Examples include hexafluoropropylene oxide oligomers represented by: This hexafluoropropylene oxide oligomer can be produced by various methods, but for example, monovalent metal fluorides, tertiary amines, oxides of tertiary amines, or quaternary ammonium salts are used as catalysts, and organic Obtained by polymerizing hexafluoropropylene oxide in a diluent.
No. 10061, No. 41-16798, and No. 41-16799).

The membrane with high oxygen gas permeability, which is the object of the present invention, can be manufactured by the following method. One example is to first synthesize a polymer derivative having a perfluoroether group in its side chain by dissolving a raw material polymer and then adding the fluorine-based acylating agent to the solution and causing a reaction. . Next, this polymer derivative is dissolved in a good solvent, cast onto a flat plate, and dried by heating to form a film, or extruded through a spinneret to form a hollow fiber, or coated on a porous membrane to form a film. There is a way to do it. Another example is a method in which a polymer that has already been formed into a thin film or hollow fiber is directly used as a raw material. That is, the film or hollow fiber is immersed in the fluorine-based acylating agent and stirred in an inert gas atmosphere, or the film or hollow fiber is reacted with the fluorine-based acylating agent in a poor solvent. In the above two methods, it is preferable to use an acid acceptor.

The oxygen permeability of the polymer membrane having perfluoroether groups in its side chains obtained by the present invention is significantly increased compared to the permeability of the non-fluorinated polymer membrane as a raw material. In other words, if a polymer with low transmittance such as cellophane or chitosan is used as a starting material, the
tens of thousands of times, even if a relatively high transmittance polymer such as ethylcellulose is used as the starting material.
It is significantly increased by 10 times compared to the raw material polymer. Also,
If the starting material polymer is a film or hollow fiber and a perfluoroether group is introduced while maintaining its shape, the active layer (non-porous layer on the surface of the film or hollow fiber) of the starting material film or hollow fiber is By making the film thin, it has the advantage that a thin highly permeable film can be easily obtained.
Using the polymer membrane obtained in this way dramatically improves oxygen permeability, so it has the potential to be used in the aforementioned artificial gills, artificial lungs, and oxygen separation membranes with high oxygen permeability. It's here.

In addition, in the present invention, the measurement of gas permeability is carried out by
The measurement was carried out using an air permeability measuring device model SK-3 manufactured by Sanko Rikagaku Kogyo Co., Ltd.

Example 1 45 g of ethyl cellulose (19% ethoxylation rate)
was dissolved in 400 ml of dry methylene chloride at room temperature, then 36 g of dry pyridine was added. Further, 97 g of CF ₃ CF ₂ CF ₂ OCF (CF ₃ )COF was added with stirring. The solution, which had been stirred for 5 hours, was poured into a 70:30 mixed solvent of methanol and water to precipitate the polymer. The supernatant solution was completely decanted and the polymer was redissolved in 1 l of acetone. This polymer was then dissolved in methanol-water (70:30).
Reprecipitate, filter, air dry, then vacuum at 90°C
It was dried. According to the infrared absorption spectrum, only trace amounts of hydroxyl groups were observed. A 10% acetone solution of this polymer was cast onto a Teflon plate and heated at 50°C for 15 hours to obtain a 19 μm thick film.

The oxygen gas permeability of the obtained membrane was 300×10 ^-10 cm ² .
cm・cm ^-2・sec ^-1・cmHg ^-1 , which is 12 times that of ethylcellulose membrane.

Example 2 Thoroughly dried 6 nylon film with a thickness of 23 μm
0.20 g of CF ₃ CF ₂ CF ₂ OCF (CF ₃ ) COF 1.8 g in 100 ml of tetrachloroethane solution (contains 7 g of pyridine)
and stirred at 100°C for 5 hours. Thereafter, the film was taken out and thoroughly washed with tetrachloroethane and then methanol. The ilm thus obtained was vacuum dried at 50°C.

The oxygen gas permeability of the obtained film was 2.0×
10 ^-10 cm ³ , cm・cm ^-2・sec ^-1・cmHg ^-1 , which is 59 times that of 6-nylon film.

Example 3 0.19 g of a sufficiently dried chitosan film with a thickness of 20 μm was
(-CF( _CF3 ) _CF2O ) _-2 CF( _CF3 )COF6.4g in 100ml dry dimethylacetamide solution (dry pyridine)
Contains 5g. ) and stirred at room temperature for 5 hours.
Thereafter, the film was taken out and thoroughly washed with dimethylacetomide. The film thus obtained was heated at 50°C.
It was vacuum dried.

The oxygen gas permeability of the obtained film was 9.4×
10 ^-10 cm ³ · cm · cm ^-2 · sec ^-1 · cmHg ^-1 , which was 9400 times that of the chitosan film.

Example 4 A sufficiently dried film of ethylene-vinyl alcohol copolymer with a thickness of 21 μm (vinyl alcohol
45% by weight) 0.21g F(-CF( _CF3 ) _CF2O ) _-4CF
(CF ₃ ) Tetrahydrofuran and trifluorotrichloroethane containing 14.7 g of COF (volume ratio 1:
10) was immersed in 140 ml of solution (containing 27 g of pyridine) and stirred at room temperature for 5 hours. Then, the film was taken out and thoroughly washed with trifluorotrichloroethane. The film thus obtained was vacuum dried at 50°C.

The oxygen gas permeability of the obtained film is 30×
10 ^-10 cm ³ · cm · cm ^-2 · sec ^-1 M · cmHg ^-1 , which was 90 times that of the ethylene-vinyl alcohol copolymer membrane.

Example 5 F
CF (CF ₃ ) CF ₂ O) - ₂ CF (CF ₃ ) COF 5.2 g in tetrahydrofuran solution 150 ml (contains pyridine 5.9 g)
and stirred at room temperature for 5 hours. Next, the hollow fiber was taken out and thoroughly washed with tetrahydrofuran. The hollow fiber thus obtained was vacuum dried at 50°C.

The oxygen gas permeability of the obtained membrane was 58×10 ^-10
cm ³ · cm · cm ^-2 · sec ^-1 · cmHg ^-1 , which is 29,000 times that of the QYPRA ammonia rayon film.

Claims (1)

[Scope of Claims] 1. A highly oxygen gas permeable membrane comprising a polymer derivative containing a perfluoroether group represented by the following general formula as a side chain substituent. 2. The highly oxygen gas permeable membrane according to claim 1, wherein the polymer derivative is one selected from the group consisting of cellulose derivatives, chitosan derivatives, povinyl alcohol derivatives, and polyacid derivatives.