JPH09173759A - Gas separating membrane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polymer material having a high permeation factor, a high separation factor and satisfactory strength as a membrane, especially a material useful for a gas separating membrane fit to obtain oxygen enriched air. SOLUTION: This gas separating membrane is made of a polymer of at least one kind of propiolic ester represented by the formula HC<=C-CO2 -R, a copolymer of a mixture of the propiolic ester with other copolymerizable monomer or a laminated body consisting of the (conpolymer and other material. In the formula, R is 1-18C alkyl, 4-12C cycloalkyl, aryl or a substituent obtd. by combining such substituents with each other and F atoms may be substd. for part or all of the H atoms in each of the substituents.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a gas separation membrane having excellent gas permeability and high separation performance. In particular, it relates to a gas separation membrane useful for enriching oxygen.

[0002]

2. Description of the Related Art All organic polymer materials have gas permeability to a greater or lesser degree, and their permeability greatly differs depending on the type of material and the type of gas. It has been known for a long time that specific components can be separated and concentrated from. In particular, gas separation using a membrane is advantageous in terms of energy compared with other separation methods, has a small size and light weight, has a simple mechanism, and is maintenance-free. Therefore, it is actively applied in various industrial fields. There is. In particular, in recent years, attention has been paid from the viewpoints of resource saving, energy saving, collection of useful gas, and the like. For example, separation of air into oxygen and nitrogen, separation and recovery of hydrogen from offgas of the platforming method, separation and recovery of hydrogen during ammonia synthesis, recovery of carbon dioxide from exhaust gas from thermal power generation and refuse incineration, and nitrogen oxides. It is used in many fields, such as the removal of sulfur oxides and sulfur oxides, the recovery of carbon dioxide from offgas in oil fields, the removal of acidic gases such as hydrogen sulfide and carbon dioxide from natural gas, and the separation and recovery of helium.

Above all, if oxygen-enriched air whose oxygen concentration is increased from the air by the membrane separation method can be easily and continuously obtained at low cost, its value is great. Currently, it is used for medical care such as a premature infant's nursery box or treatment of patients with respiratory diseases, but it is troublesome to produce or cannot be supplied continuously, and must be diluted before use. It has serious drawbacks such as that. However, if an efficient membrane capable of concentrating and supplying oxygen from air can be obtained, the above-mentioned drawbacks can be solved, and a great advance in the medical field can be expected, such as the fact that it can be used at home with a simpler device. In addition, various combustion systems currently in use, such as industrial boilers, furnaces or steel blast furnaces,
Even in internal combustion engines used for automobiles, household heating appliances, etc., if oxygen-enriched air is easily and continuously supplied using a membrane, combustion efficiency can be increased and fuel can be saved, thus saving energy. At the same time, the problem of environmental pollution due to incomplete combustion is solved. Furthermore, if the membrane supplies inexpensive and simple oxygen-enriched air, its development can be promoted also in other fields such as food industry, cultivated fishery, and waste treatment.

There are many polymer materials currently known
It has gas permeability to some extent, but it is industrially practical
Oxygen permeability is sufficiently high to make it a membrane for oxygen enrichment
And the selectivity of oxygen to nitrogen must be high.
Yes. Gas permeability is a value that is unique to polymer materials.
Performance can be compared with the over coefficient, the unit is cm ^Three
(STP) / cm / cm^Two・ Represented in sec · cmHg
You. This is low when high pressure is applied from one side across the membrane.
Volume of gas permeating to the pressure side (unit: cm^ThreeAnd
When measuring the transmission amount at 25 ° C and 1 atm as standard)
Between (sec), the pressure difference between the gas on both sides of the membrane (cmHg),
Surface area of membrane (cm^Two), And film thickness (cm)
It has been transformed. In addition, the gas separation membrane for oxygen enrichment
The number of separation systems (selection of oxygen to nitrogen
Property) can be expressed by the ratio of the oxygen permeability coefficient and the nitrogen permeability coefficient.
I can do it.

Therefore, when searching for a material for a selective gas permeable separation membrane for oxygen enrichment (oxygen-enriched membrane), a material having a large oxygen permeability coefficient must first be selected in order to obtain a practical permeation rate. is necessary. Otherwise, a large differential pressure or a large membrane surface area must be obtained, and the device becomes large and complicated. Further, in order to obtain a sufficient oxygen concentration, a polymer having a large ratio of oxygen permeability coefficient to nitrogen permeability coefficient must be selected. Furthermore, the film thickness must be thin in order to obtain the maximum permeation rate, and for that purpose, the mechanical strength of the material must be high.

That is, a film element for oxygen enrichment that is industrially practical
As materials, oxygen permeability coefficient and oxygen permeability coefficient and nitrogen permeability
It has a large ratio to the excess coefficient, and has excellent strength and durability.
Is required. However, this is
Almost none satisfy these requirements, and existing polymer
Many attempts have been made to improve it, but all have sufficient goals.
Has not reached. The oxygen permeability coefficient of existing polymers
10^-9The above are very limited and are slightly
Methyl siloxane, poly-substituted acetylene, poly-4-me
Chillpentene-1, natural rubber and the like. Other than that
Most are 10 ^-TenAnd the membrane area is extremely large
Unless it is broken, it has more practical permeation rate than these polymers.
It is not possible to obtain a film that does.

The values of the ratio of the oxygen permeability coefficient to the nitrogen permeability coefficient are at most about 3, and when the value of the oxygen permeability coefficient increases, the value of the ratio of the oxygen permeability coefficient to the nitrogen permeability coefficient also decreases. Tends to do. For example, natural rubber is a polymer having an oxygen permeability coefficient of 10 ⁻⁹ or more, but the ratio of the oxygen permeability coefficient to the nitrogen permeability coefficient is not so large, and in addition, the main chain has a double bond, so that it is durable. It cannot be used due to the serious drawback of poor (especially oxidation stability). Compared with these, poly-4-methyl-pentene-1 is not so high in gas permeability and selectivity, but has mechanical strength, heat resistance, and chemical stability (JP-A-54-54). 14
6277). Therefore, it is made into a thin film by a special processing method and is partially put into practical use as a separation membrane of an oxygen-enriching device for medical use, but its application is becoming limited from the viewpoints of processability, gas permeability, selectivity, etc. .

Polydimethylsiloxane (so-called silicone rubber) is a material having a high gas permeability and a chemical stability second to polysubstituted acetylene, but its mechanical strength is weak and it is difficult to form a thin film as it is. Therefore, special denaturation is performed to obtain a separation membrane. Due to this modification, not only the original gas permeability is considerably lowered, but also the selectivity is not improved so much, and it cannot be used in the application where a high concentration of oxygen-enriched air is required.

On the other hand, polyacetylene derivatives typified by polytrimethylsilylpropyne have the same selectivity as silicone rubber, but have gas permeability 10 times higher, and can have a higher molecular weight and a thinner film. At the beginning of the announcement of polytrimethylsilylpropyne, it attracted a great deal of attention and was studied from various viewpoints (JP-A 61-18421). An oxygen enrichment device was actually prototyped and developed on the primary market. However, it has been found that the separation performance (selectivity) of polytrimethylsilylpropyne does not change, but the gas permeation performance deteriorates with time and becomes about the same as that of silicone rubber. Various attempts have been made to improve this, but it was not sufficient and eventually the material was not used.

[0010]

As described above, with regard to the existing polymer substances, materials having a practical value of gas permeability coefficient of 10 ^-9 or more, high mechanical strength and high separation coefficient. At present, little is known, and the development of new materials that meet these requirements has been strongly desired. It is an object of the present invention to provide a polymer material having a practical permeability coefficient, sufficient strength for use as a membrane, and a sufficiently high separation coefficient. In particular, the present invention provides a gas separation membrane suitable for obtaining air having an increased oxygen concentration (oxygen-enriched air) from air.

[0011]

The first invention for achieving the above object is to provide the following general formula (1): HC≡C-CO ₂ -R (1) (wherein R in the formula is , A C1-18 alkyl group, a C4-12 cycloalkyl group, an aryl group or a substituent in which these substituents are combined with each other, and some or all of the hydrogen atoms in the substituent are fluorine atoms. Which is substituted with)), or a (co) polymer formed from a mixture with at least one propiolic acid ester represented by the formula (1) or a copolymerizable monomer. The second invention is a gas separation membrane comprising a composite of the (co) polymer described in the first invention and a porous support. The third invention is a gas separation membrane for oxygen enrichment, which uses the (co) polymer or complex described in the first invention or the second invention.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in more detail below. When R in the formula of the pyropiolic acid ester represented by the general formula (1), which is a raw material of the separation membrane material of the present invention, is an alkyl group, it is a linear or branched alkyl group having 1 to 18 carbon atoms. As typical examples, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, isobutyl group, n-amyl group, iso-amyl group, n-pentyl group, 4 -Methyl-2-pentyl group, neopentyl group,
1,1-dimethyl-2-ethylpropyl group, n-hexyl group, 2-ethylhexyl group, 2,4,4-trimethyl-2-pentyl group, n-heptyl group, n-octyl group,
Examples thereof include n-decyl group and stearyl group. Among these, those having an appropriate branched structure from the viewpoint of ease of production of propiolic acid ester, polymerization reactivity, gas permeability and chemical stability of the resulting polymer, and specific examples include isopropyl propiolate and propiolate. Neopentyl acid and 4-methyl-2-pentyl propiolate can be mentioned as preferable examples.

When R in the formula is a cycloalkyl group, it usually has 4 to 12 carbon atoms, but a cycloalkyl group having 5 to 10 carbon atoms is preferable. Specific examples thereof include cyclopentyl propiolate, cyclohexyl propiolate, cycloheptyl propiolate, and cyclooctyl propiolate. In the case of a cycloalkyl group having a substituent, for example, propioric acid (4-tert-butyl)
-Cyclohexyl, propioric acid (2-isopropyl-
5-methyl) -cyclohexyl and the like can be mentioned. Further, when R in the formula is an aryl group, a phenyl group, a biphenyl group, a naphthyl group and the like can be mentioned. However, a propiolic acid ester having an aromatic group having an excessively large number of carbons is a solid having a high melting point. Therefore, not only the polymerization reactivity is lowered, but also the gas permeability of the obtained polymer is lowered. Therefore, in the case of an aryl group substituted with an alkyl group as a preferable example, for example, propiolic acid 2-
Methyl-phenyl, 4-tert-butyl-phenyl propiolate and the like can be mentioned.

In the formula, R is a hydrogen atom in the alkyl group, cycloalkyl group or aryl group,
Those having an alkyl group, a cycloalkyl group, or an aryl group substituted with a fluorine atom, for example, 2,2
2-trifluoroethyl group, n-perfluorobutyl-2
-Ethyl group, n-perfluorooctyl-2-ethyl group,
Propiolic acid esters having a 4-trifluoromethyl-cyclohexyl group, a 2-trifluoromethyl-phenyl group, a 2,4-bis (trifluoromethyl) phenyl group can also be preferably used.

The above-mentioned propiolic acid ester can be easily synthesized by a known method. That is, the esterification reaction of propiolic acid with the corresponding alcohol, the reaction of propiolic acid chloride with the corresponding alcohol, the reaction of propioic acid chloride with the alkali metal salt of the corresponding alcohol, ethyl propiolate or methyl ester with other alcohols The target propiolic acid ester can be easily synthesized by the transesterification reaction or the like.

The present invention uses a polymer or copolymer of propiolic acid ester as a material for a selective gas permeable membrane. In the present invention, the polymer or copolymer of propiolic acid ester means a propiolic acid ester alone. Not only a polymer or a copolymer of two or more different propiolate esters but also a copolymer of a propiolate ester and another copolymerizable monomer is included.

Here, as the monomer copolymerizable with the propiolic acid ester, 1-olefins such as ethylene, propylene, 1-butene, 1-pentene and 1-heptene, monofluoroethylene, 1,2-difluoroethylene are used. , 1,1-difluoroethylene, 1,1,2-trifluoroethylene, tetrafluoroethylene, cyclohexene derivatives, norbornene derivatives, aromatic olefin monomers and the like. Furthermore, an acetylene derivative, a butadiene derivative, etc. can be used as a copolymerization partner of a propiolate ester. Among these, 1,1,2-trifluoroethylene and isobutylene can be mentioned as preferable ones. However, even if it can be copolymerized with a propiolic acid ester derivative, a copolymerization partner monomer that causes deterioration of the gas separation membrane characteristics, which is the object of the present invention, or chemical stability, durability, and film-forming property are deteriorated. Such substances, such as butadiene, are not preferred. Particularly, a copolymer with a vinyl monomer having a cyclic structure lowers gas permeability and is not preferred. Further, the copolymerizable monomer is usually added to the monomer mixture in an amount of 40
It is used in an amount of not more than 20 mol%, but is preferably not more than 20 mol% in view of the physical properties of the membrane, gas permeability and the like.

Polymers and copolymers of propiolic acid esters are known polymerization catalysts such as rhodium (Rh), tungsten (W), molybdenum (M) for the polymerization of acetylene.
By using a metal-based catalyst such as o), polymerization is relatively easy to obtain the desired polymer. For example, it is described in the following documents (Polymer Journal (Pol
ymer Journal) Vol. 22, p. 1105 (1990) and polymer (Polymer) 23
Vol., P. 744 (1982)), a polymer of a propiolic acid derivative having a relatively high yield and a high molecular weight can be obtained.

The gas separation membrane of the present invention, which comprises the propiolic acid ester polymer or copolymer as a constituent, can be easily made into a thin film by a film forming method known in the art. The solvent casting method will be described below as an example. That is, since the solubility in a solvent varies depending on the type of ester group, a casting solution is prepared using a solvent suitable for each polymer, and the casting solution is cast on a glass plate or the like to evaporate the solvent to achieve the objective. It is a method of obtaining a film having a uniform thickness. The concentration of the casting solution is suitably 0.1 to 10%, preferably 0.1 to 5%, and a thin film having a thickness of about 0.01 to 200 microns can be obtained from the solution having these concentrations. For the purpose of obtaining a large gas permeation amount, it is preferable that the film thickness is thin, and in that sense, a thickness of 0.05 to 10 microns is preferable. It is spread on the water surface using a hydrophobic organic solvent (water surface expansion). Method), and evaporating the solvent, and then scooping on the organic or inorganic porous support, a thin film of at least 1 micron or less can be formed.

The gas separation membrane composed of the (co) polymer of the present invention can be used as it is as a homogeneous membrane, but is not limited to cellulose acetate, polyamide, polyester, polycarbonate, polysulfone, polyether sulfone, polyolefin, polytetrafluoroethylene. It is better to combine a derivative, a porous support of an organic substance made of natural or synthetic fibers such as paper, etc., and a porous support of an inorganic substance such as glass, alumina, etc., to increase the film strength and use it. preferable. Specific examples of the porous support include woven cloth,
There are non-woven fabrics, porous thin films, and the like, and examples thereof include a polypropylene porous support produced by stretching treatment, a polycarbonate support made porous by using neutrons, and other cellulose-based supports used for filters. The film thickness is preferably thin, but is usually 500 microns or less, preferably 100 microns or less. The higher the porosity, the more preferable, but it is usually 30% or more, preferably 50% or more. Further, the shape of the gas separation membrane of the present invention can exhibit performance in any form such as a flat membrane, a tubular membrane, and a hollow membrane. Further, the film made of the propiolic acid ester polymer of the present invention can exhibit its characteristics when used alone, but a blend polymer obtained by mixing with another polymer such as polyolefin or polyorganosiloxane is used as a starting material. A film formed as can also be used.

[0021]

EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited thereto. Example 1 A polymerization catalyst, bis (rhodium norbornadiene chloride) ([Rh (NRD) Cl] ₂ , abbreviated as NRD in the table) was introduced from one port of a U-tube having a two-necked seal made of silicone rubber. 20 mol was added, nitrogen substitution was sufficiently performed by passing through sufficiently dried nitrogen gas, and a dry tetrahydrofuran solution containing a predetermined amount of methanol (abbreviated as MeOH in the table) was added from this port by a syringe. 4 ml of methyl propiolate (manufactured by Tokyo Chemical Industry Co., Ltd., abbreviated as MePr in the table) purified by vacuum distillation from the other mouth was injected with a syringe to prevent methyl propiolate from contacting the catalyst system. Keep it. This U-shaped tube is 40
After soaking in a constant temperature bath, the contents were thoroughly mixed and then polymerized for 24 hours. After completion of the polymerization, the content of the U-shaped tube was put into a large amount of methanol to precipitate methyl polypropiolate (abbreviated as PMePr in the table). After performing a reprecipitation purification operation in a tetrahydrofuran-methanol system,
It was dried under reduced pressure to obtain methyl polypropiolate. Table 1 shows the results of the polymerization conditions of methyl propiolate, the molecular weight of the obtained methyl polypropiolate, the polymerization yield, and the like.

[0022]

[Table 1]

0.5 g of the obtained methyl polypropiolate
Was dissolved in 50 ml of chloroform, the solution was poured into a flat petri dish having a smooth bottom, and chloroform was slowly evaporated while preventing dust and dirt from entering to form a transparent film. The film thickness was about 0.07 micron. This film was set in a cell of a high vacuum gas permeation measuring device (manufactured by NOF CORPORATION) and set at 25 ° C. First, both sides of the membrane were evacuated to a high vacuum by a diffusion pump, and then oxygen (pressure of about 40 cmH
Simultaneously with the introduction of g), the pressure change (pressure increase) on the low pressure side (vacuum side) was read and recorded by the pressure sensor. The oxygen permeation coefficient of the film was determined from the film thickness, film area, measurement time, rate of change of pressure sensor with time, supply gas pressure, device constant, and the like. Next, the oxygen gas was changed to nitrogen gas, and the nitrogen permeability coefficient was determined in the same manner as the oxygen permeability coefficient. And the oxygen transmission coefficient of methyl polypropiolate (in the table, PO
Abbreviated. The values in the table are oxygen permeation coefficients of 10 ¹⁰
The doubled one is shown. ), A nitrogen permeation coefficient (abbreviated as PN in the table. The values in the table are those obtained by multiplying the nitrogen permeation coefficient by 10 ¹⁰ ), and an oxygen permeation coefficient and nitrogen as a separation coefficient indicating selectivity. Ratio with transmission coefficient (in the table, PO / P
Abbreviated as N. ) Is shown in Table 2.

[0024]

[Table 2] (Note) The unit of transmission coefficient is × 10 ^-10 cm ³ (STP).
It is cm / cm ² · sec · cmHg (25 ° C.).

Example 2 Methyl propiolate (Me
Example 1 was repeated except that Pr) was changed to ethyl propiolate (abbreviated as EtPr in the table). The polymerization conditions and the polymerization results are summarized in Table 1. In addition, as in Example 1, after forming a uniform thin film by the solvent evaporation method, oxygen and nitrogen gas permeation measurements were performed with a high vacuum gas permeation measuring device to calculate gas permeation coefficients, and the results are summarized in Table 2. It was

Example 3 Methyl propiolate (Me
Pr) is n-propyl propiolate (in the table, n-PPr
Except that bis (rhodium-rhodium-norbornadiene) was changed to bis (rhodium cyclooctadiene chloride) ([Rh (COD) Cl] ₂ , abbreviated as COD in the table) as a polymerization catalyst. The procedure was as in Example 1.
The polymerization conditions and the polymerization results are summarized in Table 1. In addition, as in Example 1, after forming a uniform thin film by the solvent evaporation method, oxygen and nitrogen gas permeation measurements were performed with a high vacuum gas permeation measuring device to calculate gas permeation coefficients, and the results are summarized in Table 2. It was

EXAMPLE 4 Methyl propiolate (Me
The same as Example 1 except that Pr) was changed to isobutyl propiolate (abbreviated as i-BPr in the table) and methanol was changed to n-butanol (abbreviated as n-BuOH in the table) as a polymerization solvent. Went to. The polymerization conditions and the polymerization results are summarized in Table 1. In addition, after forming a uniform thin film by the solvent evaporation method in the same manner as in Example 1, the gas permeation measurement of oxygen and nitrogen is performed by a high vacuum gas permeation measuring device,
The gas permeability coefficient was calculated and the results are summarized in Table 2.

Example 5 Methyl propiolate (Me
Pr) is tert-butyl propiolate (in the table, t-B
(Abbreviated as Pr) and the procedure of Example 1 was repeated except that methanol was changed to n-butanol as a polymerization solvent. The polymerization conditions and the polymerization results are summarized in Table 1. In addition, as in Example 1, after forming a uniform thin film by the solvent evaporation method, oxygen and nitrogen gas permeation measurements were performed with a high vacuum gas permeation measuring device to calculate gas permeation coefficients, and the results are summarized in Table 2. It was

Example 6 Methyl propiolate (Me
Pr) as n-octyl propiolate (in the table, n-OcP
abbreviated as r) and methanol as a polymerization solvent.
-A procedure similar to that of Example 1 was performed except that butanol was used. The polymerization conditions and the polymerization results are summarized in Table 1. In addition, as in Example 1, after forming a uniform thin film by the solvent evaporation method, oxygen and nitrogen gas permeation measurements were performed with a high vacuum gas permeation measuring device to calculate gas permeation coefficients, and the results are summarized in Table 2. It was

Example 7 Methyl propiolate (Me
Pr) is cyclohexyl propiolate (in the table, cHPr
Abbreviated) and methanol as a polymerization solvent
The same procedure as in Example 1 was repeated except that butanol was used.
The polymerization conditions and the polymerization results are summarized in Table 1. In addition, as in Example 1, after forming a uniform thin film by the solvent evaporation method, oxygen and nitrogen gas permeation measurements were performed with a high vacuum gas permeation measuring device to calculate gas permeation coefficients, and the results are summarized in Table 2. It was

EXAMPLE 8 Methyl propiolate (Me
The same as Example 1 except that Pr) was changed to menthyl propiolate (abbreviated as MentPr in the table) and bis (chloride-rhodium-norbornadiene) was replaced with bis (chloride-rhodium-cyclooctadiene) as a polymerization catalyst. Went to.
The polymerization conditions and the polymerization results are summarized in Table 1. In addition, as in Example 1, after forming a uniform thin film by the solvent evaporation method, oxygen and nitrogen gas permeation measurements were performed with a high vacuum gas permeation measuring device to calculate gas permeation coefficients, and the results are summarized in Table 2. It was

Example 9 Methyl propiolate (Me
Example 1 was repeated except that Pr) was changed to phenyl propiolate (abbreviated as PhPr in the table). The polymerization conditions and the polymerization results are summarized in Table 1. In addition, as in Example 1, after forming a uniform thin film by the solvent evaporation method, oxygen and nitrogen gas permeation measurements were performed with a high vacuum gas permeation measuring device to calculate gas permeation coefficients, and the results are summarized in Table 2. It was

Example 10 Methyl propiolate (Me as propiolate ester
Except that Pr) was changed to a mixture (molar ratio: MePr / n-BPr = 1/1) of methyl propiolate and -n-butyl propiolate (abbreviated as n-BPr in the table).
Performed in the same manner as in Example 1. The copolymerization conditions and the copolymerization results are summarized in Table 1. In addition, as in Example 1, after forming a uniform thin film by the solvent evaporation method, oxygen and nitrogen gas permeation measurements were performed with a high vacuum gas permeation measuring device to calculate gas permeation coefficients, and the results are summarized in Table 2. It was

Example 11 Methyl propiolate (Me as propiolate ester (Me
Pr) is methyl propiolate and tert-propiolate
Mixture of butyl (molar ratio: MePr / t-BPr = 1 /
The same procedure as in Example 1 was repeated except that the procedure (1) was changed. The polymerization conditions and the polymerization results are summarized in Table 1. In addition, as in Example 1, after forming a uniform thin film by the solvent evaporation method, oxygen and nitrogen gas permeation measurements were performed with a high vacuum gas permeation measuring device to calculate gas permeation coefficients, and the results are summarized in Table 2. It was

Example 12 Methyl propiolate was used as a propiolate ester to prepare (2,2,2-trifluoro) ethyl propiolate (in the table,
F3EtPr) and the same procedure as in Example 1 except that n-butanol was used as the polymerization solvent instead of methanol. The polymerization conditions and the polymerization results are summarized in Table 1. In addition, as in Example 1, after forming a uniform thin film by the solvent evaporation method, oxygen and nitrogen gas permeation measurements were performed with a high vacuum gas permeation measuring device to calculate gas permeation coefficients, and the results are summarized in Table 2. It was

Example 13 Methyl propiolate was used as a propiolate ester and perfluorooctylethyl propiolate (in the table, F17E
(Abbreviated as Pr) and the procedure of Example 1 was repeated except that methanol was changed to n-butanol as a polymerization solvent. However, after the completion of polymerization, the content of the U-shaped tube was dissolved in trichlorotrifluoroethane (trade name: Daiflon S-3, manufactured by Daikin Industries, Ltd.), which is a fluorine-based solvent, and then precipitated with methanol and then reprecipitated. The operation was performed. The polymerization conditions and the polymerization results are summarized in Table 1. Further, a uniform thin film was prepared by the same operation as in Example 1 except that trichlorotrifluoroethane was used as the organic solvent. This film was subjected to gas permeation measurement of oxygen and nitrogen by a high vacuum gas permeation measuring device, gas permeation coefficient was calculated, and the results are summarized in Table 2.

Example 14 Methyl propiolate was used as propiolate ester in the form of -n-propyl propiolate and cyclohexene (in the table, c-
Hex) mixture (molar ratio: [nPPr] /
[C-Hex] = 2/1) A copolymer was synthesized in the same manner as in Example 1 except that 0.1 mol was changed. The polymerization results are summarized in Table 1. When the ratio of each monomer unit in the copolymer was determined by NMR (by proton), [nPPr] / [c-Hex] = 65/35
(Molar ratio). Further, the gas permeability of the copolymer was measured in the same manner as in Example 1, and the results are summarized in Table 2.

Example 15 Mixture of methyl propiolate as propiolate ester-n-propyl propiolate and 4-methyl-1-pentene (abbreviated as MePen in the table) (molar ratio:
[NPPr] / [MePen] = 4/1) 0.1 mol
A copolymer was synthesized in the same manner as in Example 1 except that The polymerization results are summarized in Table 1. The ratio of each monomer unit in the copolymer was determined by NMR (by protons) to find [nPPr] / [MePe
n] was 82/18 (molar ratio). Further, the gas permeability of the copolymer was measured in the same manner as in Example 1, and the results are summarized in Table 2.

Example 16 The poly (isobutyl propiolate) obtained in Example 4 was dissolved in toluene to prepare a 0.5 wt% solution, and this solution was allowed to stand still on a polypropylene vat filled with ion-exchanged water. Gently drop a drop on the surface of the water. This toluene solution naturally spreads on the water surface, and at the same time, toluene is evaporated and a thin film of poly (isobutyl propiolate) (water surface development film) remains on the water surface. A porous polypropylene film having a porosity of 40%, which serves as a support, is used as a support (a product of Celanese, trade name: Duraguard, a film having a thickness of 200 μm, a short diameter of 30 angstrom and a long diameter of 20).
It has a large number of 0 angstrom holes). The development of the toluene solution on the water surface and the lamination on the support were repeated 30 times. The film thickness of the obtained composite film only for poly (isobutyl propiolate) was 65 μm.
Oxygen and nitrogen permeabilities were measured by the method described in Example 1 as the composite membrane, and the results are summarized in Table 2. However, the values of the oxygen permeability and the nitrogen permeability are recalculated in consideration of the porosity of the support.

Comparative Example 1 Using the same U-shaped reaction tube as in Example 1, 1-hexyne (abbreviated as 1-Hex in the table) was used in place of methyl propiolate, and methanol was used as a polymerization solvent. n-
Polymerization was carried out under the same conditions except that butanol was used. The polymerization conditions and the polymerization results are summarized in Table 1. After forming a uniform thin film by the solvent evaporation method in the same manner as in Example 1, oxygen and nitrogen gas permeation measurements were performed by a high vacuum gas permeation measuring device to calculate gas permeation coefficients, and the results are summarized in Table 2. .

[0041]

Since the present invention is constructed as described above, the following effects can be obtained. (1) Although the gas separation membrane of the present invention has a strong strength that forms a firm film rather than rubber,
It has a large oxygen permeability exceeding 10 ^-9 . Moreover, for example, it has high performance in terms of selective permeability, and
It has a ^uniquely high value as compared with other known organic polymer materials exceeding 0-9. Selective gas permeable membranes containing these polymers as constituents become oxygen-enriched membranes in which highly concentrated oxygen-enriched air can be obtained, and for medical use, for example, oxygen-enriched membrane devices for respiratory disease patients, industrial and As various combustion systems for home use, for example, it can be used for combustion furnaces such as boilers, oil or gas heaters, and the like. (2) The gas separation membrane composed of the composite of the (co) polymer of the present invention and the porous support is further useful because the membrane strength can be significantly increased. . (3) In addition to the oxygen enrichment, hydrogen, carbon monoxide, carbon dioxide, helium, argon, hydrogen sulfide, ammonia, water vapor, or methane, ethane, propane,
It can also be used to separate a mixture of various gases such as lower hydrocarbons such as butane, ethylene, propylene and butenes.

Claims (3)

[Claims] 1. The following general formula (1) HC≡C—CO ₂ —R (1) (wherein R represents an alkyl group having 1 to 18 carbon atoms, a cycloalkyl having 4 to 12 carbon atoms). An alkyl group, an aryl group or a substituent in which these substituents are combined with each other, or some or all of the hydrogen atoms in the substituents are substituted with a fluorine atom). Or a (co) polymer formed from a mixture of the propiolic acid ester and a monomer copolymerizable therewith. 2. A gas separation membrane comprising a composite of the (co) polymer according to claim 1 and a porous support. 3. A gas separation membrane for enriching oxygen, which comprises using the (co) polymer according to claim 1 or the composite according to claim 2.