JP2010155207A - Ethylene-vinyl alcohol polymer composite-membrane for use in gas separation membrane - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a composite membrane for use in a gas separation membrane, capable of separating specific species of gasses even from a mixed gas comprising steam and excellent in water resistance. <P>SOLUTION: The ethylene-vinyl alcohol polymer composite-membrane for use in a gas separation membrane is a composite membrane that includes an ethylene-vinyl alcohol polymer (A) comprising an ethylene group by 21 to 50 mol% and an amine compound (B), and shows weight retention of 60 to 100 wt.% subsequent to submerging the same in distilled water at a temperature of 60°C for three hours. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a composite membrane for a gas separation membrane that separates a specific gas species from a mixed gas containing water vapor.

  In recent years, a separation technique using a separation membrane has been remarkably advanced. Such separation techniques include, for example, separation of liquid and solid such as separation of impurities to obtain drinking water, separation of carbon dioxide and hydrogen, or separation of carbon dioxide and methane using a selectively permeable separation membrane. Various things are included up to gas separation. In particular, gas separation technology is widely applied to off-gas in oil fields, exhaust gas from thermal power generation, carbon dioxide separation from natural gas, and the like, and technology for selectively separating carbon dioxide has been energetically studied.

  However, the conventional polymer membrane has insufficient carbon dioxide selectivity (the membrane permeation rate of carbon dioxide / the membrane permeation rate of the separation target gas), and carbon dioxide could not be recovered at the target concentration. Therefore, development of a separation membrane having excellent carbon dioxide selectivity has been desired. In order to obtain such a membrane, it has been proposed to use a material having a high selective affinity for carbon dioxide. For example, a separation membrane in which a microporous support is impregnated with a polyamidoamine dendrimer that is a liquid substance at room temperature has been proposed (Non-Patent Documents 1 and 2). Although the separation performance of the impregnated membrane shows excellent carbon dioxide selectivity exceeding 1000 in a situation where no pressure difference is provided in the membrane, when the pressure is applied to the membrane, the impregnated polyamidoamine dendrimer is separated from the support over time. It has been difficult to put it to practical use because it cannot escape and maintain its performance.

  As a method for solving this problem, a composite membrane in which a gas separation layer containing a specific amine compound in a matrix of a water-absorbing polymer material crosslinked with a crosslinking agent is formed on the surface of a porous support membrane. Has been proposed (Patent Document 1). The separation performance of this composite membrane is a separation membrane that has high selectivity and can withstand pressure differences and can be put to practical use. However, in a gas separation membrane, water vapor is often contained in the mixed gas to be separated, so that it has an appropriate hydrophilicity for expressing the affinity between the mixed gas and the membrane surface, while the water vapor over time. In particular, it is required to have the contradictory performance of water resistance without degrading the separation performance. As for the separation performance of the composite membrane, when a mixed gas containing water vapor is used, the included amine compound escapes from the composite membrane with time, and the performance cannot be maintained. The development of a separation membrane with excellent water resistance that can be used even with mixed gas is desired.

JP 2008-68238 A J. et al. Am. Chem. Soc. 122 (2000) 7594-7595 Ind. Eng. Chem. Res. 40 (2001) 2502-2511

  The present invention has been made to solve the above problems, and provides a composite membrane for gas separation membranes that is excellent in water resistance and that can separate a specific gas species even in a mixed gas containing water vapor. It is for the purpose.

  As a result of intensive studies to solve the above problems, the present inventors have obtained a composite film comprising an ethylene-vinyl alcohol-based polymer containing a specific amount of ethylene groups and a specific amine compound, and the composite film When the composite membrane is immersed in distilled water at a constant temperature for a certain period of time, the weight retention of the composite membrane is in a specific range, so that it has high selectivity and can withstand a mixed gas containing water vapor for practical use. The present inventors have found that a composite membrane for gas separation membrane having excellent water resistance that can be obtained has been obtained.

  That is, the above-mentioned problem is a composite film composed of an ethylene-vinyl alcohol polymer (A) containing 21 to 50 mol% of an ethylene group and an amine compound (B), and the composite film is dissolved in distilled water at 60 ° C. 3 The problem is solved by providing an ethylene-vinyl alcohol polymer composite membrane for gas separation membrane, wherein the composite membrane has a weight retention of 60 to 100% by weight when immersed for a period of time.

  At this time, the amine compound (B) is preferably a polyamidoamine-based dendrimer, and comprises an ethylene-vinyl alcohol-based polymer (A), an amine compound (B), and a hydrophilic polymer material (C). The weight ratio (A) / (C) of the ethylene-vinyl alcohol polymer (A) and the hydrophilic polymer material (C) is preferably 50/50 to 98/2. The hydrophilic polymer material (C) is preferably a vinyl alcohol polymer, and the ethylene-vinyl alcohol polymer (A), the amine compound (B), the hydrophilic polymer material (C) and It is preferable to consist of a polyfunctional crosslinking agent (D). Moreover, it is also a preferred embodiment of the present invention that the amount of water absorption relative to 100 parts by weight of the composite membrane is 30 to 1000 parts by weight.

  The present invention provides a composite membrane for gas separation membranes that is excellent in water resistance and can be practically used with high selectivity even if it is a mixed gas containing water vapor.

  The ethylene-vinyl alcohol polymer composite membrane for gas separation membrane having excellent water resistance of the present invention comprises an ethylene-vinyl alcohol polymer (A) containing 21 to 50 mol% of ethylene groups and an amine compound (B). A composite membrane, wherein the composite membrane has a weight retention of 60 to 100% by weight when immersed in distilled water at 60 ° C. for 3 hours.

  The ethylene unit content of the ethylene-vinyl alcohol polymer (A) used in the present invention is 21 to 50 mol%. When the ethylene unit content is less than 21 mol%, the water resistance of the composite membrane may decrease and the elution of the amine compound (B) to be blended may increase, and is preferably 23 mol% or more. More preferably, it is 25 mol% or more. On the other hand, when the content of the ethylene unit exceeds 50 mol%, the compatibility with the amine compound (B) may be reduced, and a homogeneous composite film may not be obtained, and it may be 47 mol% or less. Preferably, it is 45 mol% or less.

  The melt flow rate (210 ° C., under 2160 g load) as an index representing the degree of polymerization of the ethylene-vinyl alcohol polymer (A) used in the present invention is preferably 0.1 to 50 g / 10 min. When the melt flow rate is less than 0.1 g / 10 min, the viscosity of the solution comprising the ethylene-vinyl alcohol polymer (A) and the amine compound (B) at the time of preparing the composite film becomes too high. In some cases, not only the workability deteriorates but also a homogeneous composite film cannot be obtained. The melt flow rate is more preferably 0.5 g / 10 min or more, and even more preferably 1 g / 10 min or more. On the other hand, when the melt flow rate exceeds 50 g / 10 min, the function of constituting the matrix of the composite membrane is lowered, and the water resistance of the composite membrane may be lowered. The melt flow rate is more preferably 20 g / 10 min or less, and even more preferably 10 g / 10 min or less.

  The saponification degree of the ethylene-vinyl alcohol polymer (A) used in the present invention is preferably 95 to 99.9 mol%. When the degree of saponification is less than 95 mol%, the water resistance of the composite membrane may be lowered, and it is more preferably 96 mol% or more. On the other hand, when the degree of saponification exceeds 99.9 mol%, the workability during film formation is reduced, or the ethylene-vinyl alcohol polymer (A) and amine compound (B The viscosity stability of the solution consisting of

  The ethylene-vinyl alcohol polymer (A) used in the present invention can be obtained by saponifying a copolymer of vinyl ester and ethylene. Examples of the vinyl ester include vinyl formate, vinyl acetate, vinyl propionate, vinyl valelate, vinyl caprate, vinyl laurate, vinyl stearate, vinyl benzoate, vinyl pivalate and vinyl versatate. Among these, vinyl acetate is preferable.

  The ethylene-vinyl alcohol polymer (A) used in the present invention may further contain an anionic group or a cationic group. Monomers having a carboxyl group derived from fumaric acid, maleic acid, itaconic acid, maleic anhydride, phthalic anhydride, trimellitic anhydride, itaconic anhydride, etc. Monomers having sulfonic acid groups derived from ethylene sulfonic acid, allyl sulfonic acid, methallyl sulfonic acid, 2-acrylamido-2-methylpropane sulfonic acid, etc .; vinyloxyethyl trimethyl ammonium chloride, vinyloxy butyl trimethyl ammonium chloride , Vinyloxyethyldimethylamine, vinyloxymethyldiethylamine, N-acrylamidomethyltrimethylammonium chloride, N-acrylamidoethyltrimethylammonium chloride, N-acrylamidodimethylamine, Lil trimethylammonium chloride, methallyl trimethylammonium chloride, dimethyl allyl amine include monomers having a cationic group derived from the allyl ethyl amine. Among these monomers, maleic anhydride, maleic anhydride half ester, itaconic acid, allylsulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, from the viewpoint of availability and copolymerizability, Monomers derived from N-acrylamidomethyltrimethylammonium chloride and N-acrylamidoethyltrimethylammonium chloride are preferred. The content of these monomer units is usually 10 mol% or less, more preferably 0.1 to 8 mol%.

  The ethylene-vinyl alcohol polymer (A) used in the present invention may contain monomer units other than vinyl alcohol units and vinyl ester units as long as the effects of the present invention are not impaired. Examples of such monomer units include acrylic acid and its salts; acrylic acid esters such as methyl acrylate, ethyl acrylate, n-propyl acrylate and i-propyl acrylate; methacrylic acid and its salts; methyl methacrylate , Methacrylates such as ethyl methacrylate, n-propyl methacrylate and i-propyl methacrylate; acrylamides; acrylamide derivatives such as N-methylacrylamide and N-ethylacrylamide; methacrylamide; N-methylmethacrylamide and N-ethyl Methacrylamide derivatives such as methacrylamide; Vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether and i-propyl vinyl ether; Nitriles such as acrylonitrile and methacrylonitrile; Vinyl halides such as nyl, vinylidene chloride, vinyl fluoride, vinylidene fluoride; allyl compounds such as allyl acetate and allyl chloride; maleic acid, salts thereof or esters thereof; itaconic acid, salts thereof or esters thereof; vinyltrimethoxysilane Units derived from monomers such as isopropenyl acetate; The content of these monomer units is preferably 10 mol% or less, more preferably 5 mol% or less, and even more preferably 3 mol% or less.

  Next, the amine compound (B) will be described. The amine compound (B) can be freely selected depending on the gas to be separated. However, in the present invention, since it is necessary to have an affinity for the ethylene-vinyl alcohol polymer (A), it is preferably water-soluble or alcohol-soluble. Examples of the amine compound (B) used in the present invention include polyamidoamine-based dendrimers and other compounds such as monoethanolamine, diethanolamine, and 2,3-diaminopropionic acid as examples of carbon dioxide having a high degree of attention. , Polyallylamine, polyethyleneimine, and the like, and compounds having a primary amino group are exemplified. Polyamideamine dendrimers are preferably used in view of their large number of amino groups and carbon dioxide adsorption ability. It can be freely selected depending on the gas to be separated.

  The weight ratio (A / B) of the ethylene-vinyl alcohol polymer (A) and the amine compound (B) is not particularly limited, but is preferably 20/80 to 80/20, more preferably 30/70. It is -60/40, More preferably, it is 35 / 65-60 / 40.

  Next, the hydrophilic polymer material (C) will be described. Examples of the hydrophilic polymer material (C) used in the present invention include chitosan, hyaluronic acid, cellulose, polyvinyl alcohol, poly (p-hydroxystyrene), poly (p-aminostyrene), and poly [styrene-co- (p -Hydroxystyrene)], polyallylamine, polyvinyloxyethanol and the like. Among them, a vinyl alcohol polymer is preferable from the viewpoint of good compatibility with the ethylene-vinyl alcohol polymer (A).

  The weight ratio of the ethylene-vinyl alcohol polymer (A) and the hydrophilic polymer material (C) is not particularly limited, but the weight ratio (A) / (C) is 50/50 to 98/2. Is preferable, and 70/30 to 98/5 is more preferable. When the weight ratio (A) / (C) is smaller than 50/50, the effect of using the ethylene-vinyl alcohol polymer (A) is small, and the water resistance may be insufficient. On the other hand, when the weight ratio (A) / (C) is greater than 98/2, the effect of using the hydrophilic polymer material (C) may be reduced.

  Next, the polyfunctional crosslinking agent (D) will be described. The cross-linking agent (D) used in the present invention is a cross-linking used for cross-linking ethylene-vinyl alcohol polymers (A) or ethylene-vinyl alcohol polymers (A) and amine compounds (B). The agent is not particularly limited, and examples thereof include a compound having two or more functional groups such as an epoxy group, an aldehyde group, and a halogen atom, a titanium-based crosslinking agent, and a zirconium-based crosslinking agent. Among these, at least one selected from the group consisting of a titanium-based crosslinking agent, a zirconium-based crosslinking agent, and a crosslinking agent having an epoxy group or an aldehyde group as a functional group is preferable.

  Examples of the crosslinking agent having an epoxy group include epoxy chlorohydrin, diepoxy alkane, diepoxy alkene, (poly) ethylene glycol diglycidyl ether, (poly) propylene glycol diglycidyl ether, and (poly) glycerin diglycidyl ether. The diglycidyl ether compound is particularly preferable ethylene glycol diglycidyl ether. Examples of the crosslinking agent having an aldehyde group include dialdehyde compounds such as glutaraldehyde, succinaldehyde, malondialdehyde, terephthalaldehyde, and isophthalaldehyde, and glutaraldehyde is particularly preferable. As the titanium-based crosslinking agent, titanium alkoxide-based crosslinking agents such as titanium diisopropoxybis (triethanolaminate) and titanium lactate ammonium salt are preferable. Examples of the zirconium-based crosslinking agent include zirconium oxychloride, zirconium sulfate, zirconium nitrate, zirconium acetate, zirconium carbonate, zirconium zirconium ammonium, zirconium stearate, zirconium octylate, and zirconium silicate. Of these zirconium compounds, water-soluble ones are preferred, and those having no chlorine are more preferred. Specific examples include zirconium sulfate, zirconium nitrate, zirconium acetate, and ammonium ammonium carbonate.

  Even if the above-mentioned polyfunctional crosslinking agent (D) is used alone, performance is exhibited, but it is more effective to use a mixture of two or more different types of multifunctional crosslinking agents (D). That is, the polyfunctional crosslinking agent (D) is at least two or more selected from the group consisting of a titanium-based crosslinking agent, a zirconium-based crosslinking agent, and a crosslinking agent having an epoxy group or an aldehyde group as a functional group. Is a preferred embodiment.

  In the composite membrane of the present invention, the water absorption amount per 100 parts by weight (dry weight) of the composite membrane is preferably in the range of 30 to 1000 parts by weight. When the amount of water absorption is within this range, even if water vapor is contained in the mixed gas, it has an appropriate affinity. If the water absorption is less than 30 parts by weight, the gas separation selectivity may be reduced in a mixed gas containing water vapor, more preferably 40 parts by weight or more, and further preferably 50 parts by weight or more. preferable. On the other hand, when the water absorption amount exceeds 1000 parts by weight, water resistance is not exhibited, and therefore, the high separation performance inherent to the amine compound (B) may be deteriorated with time, and is more preferably 800 parts by weight or less. More preferably, it is 500 parts by weight or less.

  In the present invention, when the composite membrane is immersed in distilled water at 60 ° C. for 3 hours, the weight retention of the composite membrane is in the range of 60 to 100% by weight. When the weight retention is in this range, the composite membrane of the present invention that has water resistance and does not deteriorate separation performance can be obtained. If the weight retention is less than 60% by weight, the purpose of immobilizing the amine compound (B) on the ethylene-vinyl alcohol polymer (A) matrix is not achieved, and the high separation performance inherent to the amine compound (B). May not be obtained, and the water resistance may decrease, and it is preferably 70% by weight or more.

  In order to make the water absorption and weight retention in the composite membrane of the present invention within the above ranges, the kind and the use ratio of the ethylene-vinyl alcohol polymer (A) and the amine compound (B) are appropriately selected. Can be done.

  The amount used when using the polyfunctional crosslinking agent (D) is preferably 0.1 to 70 parts by weight with respect to 100 parts by weight of the ethylene-vinyl alcohol polymer (A). More preferably, it is -60 weight part. If the amount is less than 0.1 parts by weight, the resulting composite membrane may not have sufficient water resistance, and if it exceeds 70 parts by weight, high separation performance inherent to the amine compound (B) may not be obtained. There is.

  The heat treatment of the composite membrane is important from the viewpoint of obtaining the ethylene-vinyl alcohol polymer composite membrane for gas separation membrane having excellent water resistance of the present invention. By promoting the crystallization of the ethylene-vinyl alcohol polymer (A) by heat treatment, an effect such as crosslinking can be exhibited. As temperature of heat processing, 60-200 degreeC is preferable and 90-180 degreeC is still more preferable. If it is lower than 60 ° C., the effect of heat treatment may be insufficient. If it exceeds 200 ° C., the ethylene-vinyl alcohol polymer (A) and the amine compound (B) may be decomposed, which is not preferable. The heat treatment time varies depending on conditions and equipment and is not particularly limited, but is preferably in the range of 1 second to 1 hour. If it is less than 1 second, the effect of heat treatment may be insufficient. If it exceeds 1 hour, it is not preferable because not only industrial implementation is difficult, but also the ethylene-vinyl alcohol polymer (A) and the amine compound (B) may be decomposed.

  The ethylene-vinyl alcohol-based polymer composite membrane having excellent water resistance according to the present invention is suitably used as a gas separation membrane that can withstand a mixed gas containing water vapor and can be used practically. The gas separation membrane is composed of a support membrane and the composite membrane of the present invention, and the composite membrane of the present invention is formed on the surface of a known support membrane. As the hydrophobic polymer constituting the support membrane, a conventionally known resin for film formation can be used. Examples of the hydrophobic resin include polysulfone, polyethersulfone, polyamide, polyimide, polyacrylonitrile, polystyrene, polyvinylidene fluoride, polyvinyl chloride, polyamide, polymethyl methacrylate, and the like.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in more detail, this invention is not limited at all by these Examples. Unless otherwise specified in the examples, “%” and “part” mean “% by weight” and “part by weight”, respectively.

[Water resistance evaluation of composite membrane]
The amount of water absorption and the weight retention rate of the sheet-like material were determined by the following equations, respectively.
Water absorption (parts) = [(W1 / W2) -1] × 100
Weight retention (%) = {1-[(W3-W2) / W3]} × 100
In the above formula, the symbols have the following meanings.
W1: Weight of sample after swelling W2: Sample weight after swelling and further drying W3: Sample weight before swelling

Synthesis example 1
[Synthesis example of vinyl alcohol polymer having ethylene unit]
A 100 L pressurized reaction vessel equipped with a stirrer, nitrogen inlet, ethylene inlet and initiator addition port was charged with 56 kg of vinyl acetate and 5.8 kg of methanol, heated to 60 ° C., and then subjected to nitrogen bubbling for 30 minutes. Was replaced with nitrogen. Then the reaction vessel pressure was introduced charged ethylene to be 6.0 kg / cm ^2. A 2.8 g / L solution in which 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile) was dissolved in methanol as an initiator was prepared, and nitrogen substitution was performed by bubbling with nitrogen gas. After adjusting the temperature inside the reaction vessel to 60 ° C., 50 mL of the initiator solution was injected to initiate polymerization. During the polymerization, ethylene was introduced to maintain the reactor pressure at 7.0 kg / cm ² , the polymerization temperature at 60 ° C., and the above initiator solution was continuously added at 170 mL / hr. After 6 hours, when the polymerization rate reached 40%, the polymerization was stopped by cooling. The reaction vessel was opened and deethylene removed, and then nitrogen gas was bubbled to completely remove ethylene. Subsequently, the unreacted vinyl acetate monomer was removed under reduced pressure to obtain a methanol solution of polyvinyl acetate (hereinafter abbreviated as PVAc). The solution adjusted to 20% was saponified by adding a NaOH methanol solution (concentration of 10%) having a molar ratio (number of moles of NaOH / number of moles of vinyl acetate units in polyvinyl acetate) of 0.05. The degree of saponification of the obtained PVA (PVA-1) was 98.6 mol%.

  After polymerization, the methanol solution of PVAc obtained by removing the unreacted vinyl acetate monomer was precipitated in n-hexane and reprecipitation purification was performed three times by dissolving with acetone, and then dried at 60 ° C. under reduced pressure to obtain purified PVAc. Obtained. The amount of ethylene modification determined by measuring the alkali consumption of PVAc was 5.5 mol%. After saponifying the above methanol solution of PVAc at an alkali molar ratio of 0.2, methanol Soxhlet was carried out for 3 days and then dried to obtain purified PVA. It was 1680 when the average degree of polymerization of this PVA was measured according to JIS K6726 of the usual method.

Example 1
Eval F101B (ethylene 32 mol%, melt index 3.8 g / 10 min, saponification degree 99.7 mol%, manufactured by Kuraray Co., Ltd.) was gradually added to a solution of water / isopropyl alcohol = 40/60, and when it became a slurry state, 95 Heated to 0 ° C. to prepare a 3 wt% aqueous solution. 15 parts by weight of a 20% methanol solution (manufactured by Aldrich) of PAMAM dendrimer (surface group: —CONHCH ₂ CH ₂ NH ₂ , number of surface groups: 4) as an amine compound (B) with respect to 100 parts by weight of the aqueous solution. The mixture was gradually added while stirring. This solution was cast and dried at 60 ° C. to obtain a sheet-like material having a thickness of 100 μm. The obtained sheet was fixed to a frame and heat-treated at 120 ° C. for 10 minutes with a hot air dryer. The heat-treated sheet was immersed in warm water (60 ° C.) for 3 hours, and the water absorption and weight retention were measured. The sheet-like product had a water absorption of 160 parts by weight and a weight retention of 79%, maintaining a firm film state. The results are shown in Table 1.

Comparative Example 1
Chitosan having a molecular weight of 500,000 (trade name: Chitosan H, manufactured by Kimika Co., Ltd.) / Chitosan having a molecular weight of 50,000 (trade name: Chitosan LL, manufactured by Kimika Co., Ltd.) = 100/10 mixed chitosan was gradually added to a 2% by weight aqueous solution of acetic acid. In addition, the mixture was stirred for 60 minutes to prepare a 0.5 wt% chitosan solution. Thereafter, 20 parts by weight of ethylene glycol diglycidyl ether (EGDGE) (manufactured by Tokyo Chemical Industry Co., Ltd.) as a crosslinking agent (D) is gradually added to 100 parts by weight of an aqueous acetic acid solution of chitosan filtered through a 1.0 μm filter paper. In addition to the adjustment. This solution was cast and dried at 20 ° C. to obtain a sheet-like material having a thickness of 100 μm. The obtained sheet was fixed to a frame and immersed in a large excess of 0.1 M aqueous sodium hydroxide solution for 10 minutes. Subsequently, it was immersed in a mixed solvent of distilled water and ethanol 1: 1 for 60 minutes, and then dried at 60 ° C. for 8 hours.

  Furthermore, the dry sheet-like material fixed to the obtained frame was diluted twice with water in the same 20% methanol solution (manufactured by Aldrich) of PAMAM dendrimer as that used in Example 1 as the amine compound (B). It was immersed in a large excess of solution for 30 minutes. Thereafter, it was dried at 60 ° C. for 8 hours. From the weight measurement, the sheet-like material contained 100 parts by weight of PAMAM dendrimer with respect to 100 parts by weight of chitosan. Further, heat treatment was performed at 120 ° C. for 10 minutes. The heat-treated sheet was immersed in warm water (60 ° C.) for 3 hours, and the water absorption and weight retention were measured. The sheet had a water absorption of 170 parts by weight and a weight retention of 36%, and the film state was firm, but the weight retention was low. The results are shown in Table 1.

Comparative Example 2
Instead of EGDGE, which is the crosslinking agent (D) used in Comparative Example 1, a sheet-like material heat-treated in the same manner as in Comparative Example 1 except that 3 parts by weight of glutaraldehyde (GA; manufactured by Wako Pure Chemical Industries, Ltd.) was used. Obtained. The weight retention was low. The results are shown in Table 1.

Examples 2-4, Comparative Examples 3-4
The same procedure as in Example 1 was performed except that the type of ethylene-vinyl alcohol polymer used in Example 1 was changed to that shown in Table 1. The results are shown in Table 1.

Examples 5-7
Using Eval F101B used in Example 1, PVA-1 obtained in Synthesis Example 1 as a hydrophilic polymer (C), PVA-2 synthesized in the same manner as Synthesis Example 1, and PVA-205 ( The same procedure as in Example 1 was performed except that the weight ratio of (A) / (C) and the heat treatment temperature of the sheet were changed to those shown in Table 1 using Kuraray Co., Ltd. The results are shown in Table 1.

Examples 8-12
Table 1 shows the weight ratio of (A) / (C) using the ethylene-vinyl alcohol polymer (A) used in Example 2 and the hydrophilic polymer (C) used in Examples 5 and 6. The same procedure as in Example 5 was performed except that the one shown in FIG. The results are shown in Table 1.

Examples 13-14
A crosslinking agent (D) was newly added, and the ethylene-vinyl alcohol polymer (A), the hydrophilic polymer (C) and the crosslinking agent (D) weight ratios were changed to those shown in Table 1, except that The same operation as in Example 8 was performed. The weight retention was high and the water resistance was improved. The results are shown in Table 1.

Examples 15-16
Except using two types of crosslinking agents, it carried out similarly to Example 13 and 14, and obtained the heat-treated sheet-like material. The obtained sheet was fixed to a frame and immersed in an aqueous sulfuric acid solution in an amount equal to glutaraldehyde at 60 ° C. for 10 minutes. Subsequently, it was immersed in a mixed solvent of distilled water and ethanol 1: 1 for 60 minutes, and then dried at 60 ° C. for 8 hours. The results are shown in Table 1.

Comparative Example 5
Table without using ethylene-vinyl alcohol polymer (A), using PAMAM dendrimer as amine compound (B), PVA-120 as hydrophilic polymer (C), and glutaraldehyde as crosslinking agent (D). The same procedure as in Example 15 was performed at the weight ratio shown in FIG. When the obtained sheet was immersed in warm water at 60 ° C., the sheet was dissolved.

Comparative Example 6
The same procedure as in Example 1 was conducted except that the weight ratio (A / B) of the ethylene-vinyl alcohol polymer (A) and amine compound (B) in Example 1 was changed to that shown in Table 1. Weight retention decreased to 49%. The results are shown in Table 1.

Claims (6)

  A composite film comprising an ethylene-vinyl alcohol polymer (A) containing 21 to 50 mol% of an ethylene group and an amine compound (B), wherein the composite film is immersed in distilled water at 60 ° C. for 3 hours An ethylene-vinyl alcohol polymer composite membrane for gas separation membrane, wherein the composite membrane has a weight retention of 60 to 100% by weight.   The ethylene-vinyl alcohol polymer composite membrane for gas separation membrane according to claim 1, wherein the amine compound (B) is a polyamidoamine dendrimer.   The weight of the ethylene-vinyl alcohol polymer (A), the amine compound (B) and the hydrophilic polymer material (C), and the weight of the ethylene-vinyl alcohol polymer (A) and the hydrophilic polymer material (C). The ethylene / vinyl alcohol composite membrane for gas separation membrane according to claim 1 or 2, wherein the ratio (A) / (C) is 50/50 to 98/2.   The ethylene-vinyl alcohol composite membrane for gas separation membrane according to claim 3, wherein the hydrophilic polymer material (C) is a vinyl alcohol polymer.   The ethylene for gas separation membrane according to claim 3 or 4, comprising an ethylene-vinyl alcohol polymer (A), an amine compound (B), a hydrophilic polymer material (C), and a polyfunctional crosslinking agent (D). -Vinyl alcohol polymer composite film. The ethylene-vinyl alcohol composite membrane for gas separation membrane according to any one of claims 1 to 5, wherein the amount of water absorption relative to 100 parts by weight of the composite membrane is 30 to 1000 parts by weight.