JPS5892449A - Membrane for selective permeation of oxygen gas - Google Patents

Abstract

PURPOSE:To obtain the membrane through which oxygen gas can selectively permeate as compared with other gases, esp. nitrogen gas, by forming the selective oxygen gas-permeable membrane from a macromolecular derivative contg. a specified side-chain-substituted group. CONSTITUTION:The selective oxygen gas-permeable membrane is formed from a macromolecular derivative contg. a side chain-substituted group defined by the formulaI(where, Y=F, Cl, etc., m=0 or 1 and n=1-10) such as a cellulose or alcohol derivative. This permeable membrane is useful, since it makes oxygen gas permeate through it with a large ratio of oxygen permeation as compared with other gases, esp. nitrogen gas.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a selectively permeable membrane that can selectively permeate oxygen gas to other gases, II#, compared to a nitrogen bus, and has a high oxygen permeability. Technology to separate oxygen from mixed gas, I! The technology to separate oxygen from air is useful. That is, it can be used in fermentation engineering, aeration for sewage treatment, aeration for fish culture, etc. Furthermore, if Jin's technology is applied to various combustion appliances and automobile engines, it will help save energy and prevent pollution. Furthermore, air containing 30-40% oxygen is necessary for patients with impaired lung function and premature infants, and its application in this area is also useful for medical purposes.

By the way, as conventional O separation methods, there are cryogenic separation methods and one-coat methods in addition to membrane separation, but both have disadvantages such as requiring large equipment and high energy costs. On the other hand, there is a method of oxygen separation that requires less energy and requires relatively simple equipment and operation, using membrane separation. However, membrane separation of oxygen gas has rarely been put to practical use. The necessary conditions for an oxygen separation membrane are a high ratio of oxygen and nitrogen permeability coefficients, a high oxygen permeability, sufficient mechanical strength, and sufficient chemical resistance depending on the application: There are four things that can be mentioned,
This is because a polymer membrane that satisfies these requirements simultaneously has not been realized.

For example, silicone rubber is used as a typical conventional surface oxygen separation membrane, but it has the drawback of having a small oxygen to nitrogen permeation ratio of about 2.

Additionally, some polymer membranes have a permeability ratio as high as Ks, such as polyethylene terephthalate membranes, but these O membranes have a problem of low oxygen permeability. As a method to improve both of these problems, a method of introducing a neutralizing fluorine compound into a polymer film already exists. That is, a method has been proposed in which a polymer membrane containing a fluoroacylated ethyl cellulose derivative is used as a gas-permeable membrane for a blood oxygen supply device. However, when compared with non-fluorinated ethyl cellulose, its oxygen gas permeability is about 1.9~
The increase is only 3.0 times, which is insufficient.

The present inventors discovered that rI! has a large oxygen to nitrogen permeation ratio and a high oxygen permeability! As a result of extensive research into elemental separation J[K, we discovered that a polymer membrane with a specific fluorine-containing substituent was suitable for the purpose, and based on this knowledge, we completed the present invention.

That is, the present invention provides an oxygen gas selective permeable membrane characterized by being made of a polymer derivative containing the following general formula as a side chain substituent.

(Y:F, C2, Br or aI mho or 1.ms1-10) The polymer into which the perfluoroether substituent group is introduced is a polymer having functional groups such as hydroxyl group, amino group, and group that reacts with acid fluoride. Examples of such polymers include cellulose polymers, chitosan polymers, boria-based polymers, and vinyl alcohol polyesters. - I can say things like jin and ゛. Examples of cellulosic polymers include ethyl cellulose, methyl cellulose, hydroxyethyl cellulose, ethyl hydroxyethyl cellulose, carboxymethyl heptose and its salts, cellulose nitrate, cellulose acetate, and mixed esters of cellulose. As a chitonan-based polymer,
Examples include ether chitosan, methyl chitosan, acetic acid chitosan, carboxymethyl chitosan and its salts, and hydroxyethyl chitosan. As polyand, 6
-6 nylon, 6 nylon, ull imine @ -10 nylon, inphthalic acid chloride and m-phenylenediamine copolymer, m-xylene diamine and adipic acid copolymer, etc. Examples of vinyl alcohol polymers include polyvinyl alcohol, vinyl alcohol copolymer, and partially saponified polyvinyl acetate.

The functional groups that react with the fluoride contained in the poly-r-11c used in the present invention include the above-mentioned hyperkinetic group, hydroxyl group, amino group, or amide group. In order to achieve the intended purpose, it is necessary that the amount of reacting nuclear functional groups (ano groups, hydroxyl groups, abado groups, etc.) is on average 10 - or more by weight of the polymer. When the average weight is less than 10%, the effect of the fluorine-containing substituent can be sufficiently exhibited, and the increase in transmittance ratio and transmittance is small.

The structure of the other raw material to be reacted with the polymer used in the present invention is (Y: F + CL + Br*tUIm:
O or 1. n: 1-10 0) hereinafter referred to as perfluoropolyether. It is. This manufacturing method is known. For example, tne'l's method for producing perfluoropolyethers uses a monovalent metal fluoride, a tertiary amine, or an oxide of a tertiary amine, or a quaternary metal fluoride, or a tertiary amine.
The hexafluorolog μpyrene oxide may be polymerized in an organic diluent using a grade ammonium salt or the like as a catalyst. (
(Japanese Patent Publications No. 40-10061, No. 41-16798, and No. 41-167Ii1)) The polymer membrane having perfluoropolyether groups in the side chains, which is the object of the present invention, is made by combining the above polymer with perfluoropolyether groups. Form hly by treatment with ether. There are two methods of processing. One method is to dissolve the derived polymer and then add perfluoropolyether to the solution for reaction.The resulting polymer derivative is dissolved in a good solvent, cast on a flat plate, and heated. It may be dried to form a film. Another method is to directly use a polymer that has already been formed into a thin film or hollow core as a raw material. That is, it can be obtained by immersing a film or hollow fiber in perfluoropolyether and stirring in an inert gas atmosphere, or by subjecting the film or hollow fiber to a perfluoropolynitrate reaction in a poor solvent. Above 2
In the method of treating hyperactivity, it is preferable to use acid receptors.

The oxygen and nitrogen permeability ratio of the polymer membrane having perfluoropolyether groups in the side chains obtained in the present invention is significantly increased compared to the permeation ratio of the non-fluorinated polymer membrane as a raw material. On the other hand, the oxygen permeability is hundreds to tens of thousands of times higher when using polymers with low permeability such as celone or chitosan as the starting material, and when using polymers with relatively high permeability such as ethyl cellulose as the starting material. Even when used, the increase is approximately 10 times greater than that of the original polymer. In addition, if the starting material polymer is a film or hollow fiber and a perfluoropolyether group is introduced while maintaining its shape, the separation membrane can be formed by thinning the original film or hollow fiber. It has the advantage of being easy to make into a thin film.

Using the polymer membrane obtained in this way dramatically improves oxygen separation, opening the possibility of its use in the aforementioned combustion devices and medical applications.

In the present invention, gas permeability is measured using an air permeability measuring device 5K-32 manufactured by Sangen Rikagaku Kogyo ■. ! ! This was done using

Example 1 Ethyl cellulose (ethoxylation rate of 4.-) asp,
0 further 1 CF dissolved in 400 wIt of dry methylene chloride at room temperature and then added with dry pyridine uf,
CF, CF, OCF (CF, ) COF @7
t was added with stirring. The solution that had been stirred for 5 hours was poured into a mixed solvent of methanol and water O70:36.
The polymer was precipitated. Decant the supernatant solution completely;
It is also possible to redissolve the polymer in acetone. This poly! - was then reprecipitated in methanol-water (To:M), filtered, air-dried, and then dried in vacuo at 100°C. Infrared absorption spectra showed only trace amounts of hydroxyl groups.

A solution of this polymer in 1-thiacetone was cast on a TEA plate and heated at 50°C for 11 hours to obtain a film with a thickness of 19 mm.The gas permeability of the resulting film was measured. The oxygen to nitrogen permeation ratio of this membrane was significant, 3.1 times that of the ethyl cellulose membrane. In addition, the oxygen gas permeability fl, 3
00 X 1@-'aias・am-"・5ee-
"・txBf-" was 10, which was 1 times as much as the ethyl cellulose membrane.

Example 2 Thoroughly dried 6 nylon film o, z with thickness t8fi
o r, CF, CF, CF, 0CF(CF,)COF
L, S t tetrachloroethane solution 100 vt
(Contains 7F of pyridine.) Soaked in K, Zoo℃ for 5 hours
The film was then taken out and thoroughly washed with dichloroethane and then methanol. The film thus obtained was vacuum dried at goC.

The gas permeability of the obtained film was kept constant at 0. The permeation ratio of oxygen and nitrogen of this membrane was 4.8 times that of the 6-day film. The rate is
2.0 X 10-”°aits・az-”・5ee
Example 3 A fully dried thick cast μO chitonan film o, is t, which was 59 times that of a 9.6 nylon film, was
+CF(CF,)CF,O+ICF(OF,)COF
6.4 F dry dimethylacetamide solution 100
II/ (containing dry viridiy5t), stirred at room temperature for 5 hours, then removed, washed thoroughly with dimethylacetamide, and vacuum-dried at H°C.

The gas permeability of the obtained film was measured. The oxygen to nitrogen permeability ratio of this membrane was 16, which was 3.0 times that of the chitosan membrane. Also, the oxygen gas permeability is 9.4
10-"d-cs・cm-'・5ea-' ・an
Hy-'', which was about 34,000 times that of the chitosan film.

Example 4 Thoroughly dried ethylene-vinyl aluminum with a thickness of 21 μm: f
-L copolymer film (vinyl alcohol 45iit
%)021F I-+CF(CF,)CF,0-)4C
F(CFs)COF 16.8 f nato2hydrof9
The mixture was immersed in a solution of 140 sd (containing 72'lf of pyridine) K and stirred at room temperature for 5 hours. Next, the film was taken out and thoroughly washed with tetrahydrofuran. The film thus obtained was vacuum dried at 50°C.

The gas permeability of the obtained film was measured. The oxygen to nitrogen permeation ratio of this film was 17, which was 4.3 times the permeation ratio of the ethylene-vinyl alcohol co-I composite film. Also, the oxygen gas permeability is 41 x 1G-”
aLcs・m−L 5ee−′・erIIHy−heavy.

Example 5 Sufficiently dried Kiep 2 with an inner diameter of 200 JS and a film thickness of 20μ
Ammonia rayon hollow fiber 0.24 t wo, F+C
FtCF, 5cF10)1CF(CF3)cOF s
, z t of tetrahuman I:+7 ten solution zso w (
Contains 5.91 pyridine. ) and stirred at room temperature for 5 hours. Then, the hollow fibers were taken out and thoroughly washed with Tetrahydro 7ran. The hollow fiber thus obtained was vacuum dried at 50° C. The gas permeability of the obtained membrane was measured. The permeation ratio of oxygen and nitrogen of this membrane was 74, which was 11 times the permeation ratio of the membrane of Kiep 2 Ammonia Rayo/0. Oxygen gas permeability is 58 x 10" d・an cs-"@ee
-"・anHy-', which was about 2900Q times that of the KIEPL ammonia rayon film.

Patent Applicant Asahi Kasei Kogyo Co., Ltd. Procedural Amendment (Voluntary) Date of 1975, Month io, Commissioner of the Japan Patent Office Shima 1) Haruki Tono1, Indication of Case Patent Application No. 1988 tso@s
i No. 2 Title of the invention Oxygen gas selectivity Toyo Gen a Relationship with the case of the person making the amendment Patent applicant 1-2-6-Tun Dojimahama, Kita-ku, Osaka-shi, Osaka Target of the amendment h Contents of the amendment (1) # 4 Specification No. 3 jjlIIs line “Transmembrane ratio” is changed to “
Transmission ratio” is corrected.

(2) On page 6, line 4, "amide group 1, etc.)" is corrected to "amide group, etc.)."

(3) On page 1, line 13, "hollow child" is corrected to "hollow fiber."

(4) Page 11, line 5 [9,4X1G”J is replaced by “9.4
X 1 (corrected as 1″′″ town.

(5) 11i1, page 11, line 6 “about 840 (1(I
Double J tr 5aoo bond” is corrected.

(6) On page 12, line 1s, change “approximately zseoo times” to “zs
Correct it as oool.

that's all

Claims (3)

[Claims] (1) An oxygen-selective permeable membrane (Y: F, Ct, 1rt7t! m: O1, n: x -10) (2) The polymer derivative is one selected from the group consisting of a rhinoceros derivative, a chitonan derivative, a polyvinyl alcohol derivative, and a polyvinyl alcohol derivative. Oxygen gas selective permeable membrane (3) The oxygen gas selective permeable membrane according to claim 1, where m=1.