JP2003038942A - Separation membrane - Google Patents

Abstract

(57) [Summary] (Modified) [Problem] A separation membrane having excellent processability and excellent mechanical strength, particularly tensile strength, while maintaining excellent gas separation performance and permeation characteristics for oxygen / nitrogen separation. To provide. A separation membrane comprising a condensation polymer c comprising repeating units a and b, wherein a is formed by polycondensing a dicarboxylic acid, a tetracarboxylic acid or a derivative thereof with a diamine, triamine, tetraamine or dihydrazide. A separation membrane consisting of only the unit a, b is a unit obtained by polycondensation of dicarboxylic acid, tetracarboxylic acid or a derivative thereof, and diamine or dihydrazide, A separation membrane formed of only the unit b, wherein the ratio between the repeating units a and b is 99: 1 to 70:30 in molar ratio, has an oxygen / nitrogen separation coefficient of 7 or more, and 35 A separation membrane having a tensile strength of １００100 (MPa).

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a separation membrane having a good balance between separation performance and permeation performance and excellent mechanical strength.

[0002]

2. Description of the Related Art Separation of substances by a membrane is energetically advantageous as compared with other separation methods, and is a small and lightweight device.
Because of its simple mechanism and maintenance-free features, it is actively applied to various industrial fields. The basic performance requirements of a separation membrane are (1) separation performance between the target substance and other components, (2) substance permeation characteristics, (3) processability of membrane, mechanical strength, heat resistance, durability, resistance It is the performance of solvents. The material permeation property of the membrane is a property that mainly controls the required membrane area, the size of the membrane module and the device, that is, the initial cost. Therefore, the development of a material with high substance permeation characteristics and the separation active layer (dense layer) The thin film realizes industrially practical performance. On the other hand, in the case of a dense membrane, the substance separation characteristic of the membrane is essentially a characteristic peculiar to the membrane material, and is a characteristic that mainly controls the yield of the separated substance, that is, a characteristic that controls the running cost.

In general, the substance separation property and the substance permeation property of a membrane are in a conflicting relationship, and development of a membrane material having an excellent balance of both properties has been actively made. In particular, in the field of gas separation, it is well known that aromatic polymer materials have excellent substance separation characteristics and substance permeation characteristics, so research using various aromatic polymer materials is actively conducted. Has been done.

For example, polymer processing, Vol. 41, 16
(1992), Kogaku, Vol. 42,682 (199
3), Polymer, Vol. 35,4
970 (1994), Journal of Membrane
Science (Journalof Membrane
Science), 88, 37 (1994), Proceedings of the Polymer Society of Japan, Vol. 43, 2273 (1994), Surface, Vol. 33, 308 (1995), journal
Of membrane science (Journal of
Membrane Science), 111, 16
9 (1996) and the like, many research examples centering on polyimide, polyimidazopyrrolone and the like have been reported in reports and reviews.

As described above, in recent years, aromatic polymer materials have a particularly good balance between gas separation characteristics and substance permeation characteristics among many polymer materials, and have durability, heat resistance, solvent resistance, etc. It has been discovered that it has excellent performance as well, and research on gas separation membranes and pervaporation membranes having a non-porous dense layer of aromatic polymer has been actively conducted.

However, conventionally, for example, in a region containing a high purity gas covered by competitive technologies such as cryogenic separation and adsorption method (PSA), an oxygen / nitrogen gas separation coefficient of 7 or more is required, which is excellent. Those having gas separation characteristics and gas permeation characteristics are hard and brittle, so that there is no separation membrane that is practically satisfactory. That is, the mechanical strength that can be practically used with a material having excellent gas separation characteristics and gas permeability characteristics,
In particular, the tensile strength was not obtained, and for example, when tension was applied to the hollow fiber in the step of modularizing the hollow fiber membrane, cracking was likely to occur and it was difficult to handle. Therefore, in order to obtain a tensile strength that can be practically used, the only method is to use a separation membrane having an oxygen / nitrogen separation coefficient of about 5 to 6.

Further, the degree of polymerization of the polymer is also one of the factors that govern the processability, mechanical strength, etc., but the aromatic polymer monomer, which is excellent in substance separation characteristics and substance permeation characteristics, is not always high. It does not always exhibit polymerization reactivity, and it has not been possible to easily obtain one with a high degree of polymerization until now, and the obtained polymer material lacks practically sufficient processability and mechanical strength (especially tensile strength). Therefore, various solvents, polymerization accelerators, and the like have been tried in order to increase the degree of polymerization, but a definitive solution has not been found.

[0008]

DISCLOSURE OF THE INVENTION Problems to be solved by the present invention include an oxygen / nitrogen separation coefficient of 7 or more and an oxygen permeability coefficient of 1 × 10 ⁻¹⁰ [cm ³ / cm ² · sec · cmH.
g] It is an object of the present invention to provide a separation membrane having excellent processability and excellent mechanical strength, particularly tensile strength while maintaining the following excellent gas separation performance and gas permeation characteristics.

[0009]

[Means for Solving the Problems] As a result of intensive studies to solve the above problems, the results show that the permeability is extremely low,
Separability is relatively good, and a condensation-type polymer obtained by partially copolymerizing a monomer component rich in reactivity with polyimide or polyhydrazide imide has mechanical properties,
The inventors have found that the present invention is excellent in processability and the like, and practically does not impair the separation performance even when compared with the original material, and completed the present invention.

That is, the present invention provides the repeating unit (a)
And a repeating unit (b) comprising a condensation polymer (c), wherein the repeating unit (a) is
A unit obtained by polycondensing a dicarboxylic acid, a tetracarboxylic acid or a derivative thereof, and a diamine, a triamine, a tetraamine or a dihydrazide, wherein the separation membrane (a ′) formed only from the unit (a) is oxygen. / Nitrogen separation coefficient α _a 7 or more, oxygen permeability coefficient 1 × 10 ⁻¹⁰
[Cm ³ / cm ² · sec · cmHg] or less,

The repeating unit (b) is a unit obtained by polycondensing a dicarboxylic acid, a tetracarboxylic acid or a derivative thereof and a diamine or dihydrazide, and is a unit formed only from the unit (b). The membrane (b ') has a difference in oxygen / nitrogen separation coefficient α _b from α _a of 2 or less and an oxygen permeability coefficient of 1 × 10 ⁻¹⁰ [cm ³ / cm ² · sec ·
cmHg] or less, tensile strength 100 to 300 (MP
a), wherein the repeating unit (a) and the repeating unit (b) are in a molar ratio of 99: 1 to 70:30,
Having an oxygen / nitrogen separation factor of 7 or more, and 35 to 10
The present invention provides a separation membrane characterized by having a tensile strength of 0 (MPa).

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION A separation membrane formed from a condensation polymer (c) comprising a repeating unit (a) and a repeating unit (b), wherein the repeating unit (a) is a dicarboxylic acid or a tetracarboxylic acid. Alternatively, a separation membrane (a ′) which is a unit obtained by polycondensing a derivative thereof and diamine, triamine, tetraamine or dihydrazide, and which is formed only from the unit (a) has an oxygen / nitrogen separation coefficient α. _a
7 or more, oxygen permeability coefficient 1 × 10 ⁻¹⁰ [cm ³ / cm
² sec / cmHg] or less,

The repeating unit (b) is a unit obtained by polycondensing a dicarboxylic acid, a tetracarboxylic acid or a derivative thereof and a diamine or a dihydrazide, and is a unit formed only from the unit (b). The membrane (b ') has a difference in oxygen / nitrogen separation coefficient α _b from α _a of 2 or less and an oxygen permeability coefficient of 1 × 10 ⁻¹⁰ [cm ³ / cm ² · sec ·
cmHg] or less, tensile strength 100 to 300 (MP
a), wherein the repeating unit (a) and the repeating unit (b) are in a molar ratio of 99: 1 to 70:30,
Having an oxygen / nitrogen separation factor of 7 or more, and 35 to 10
A separation membrane having a tensile strength of 0 (MPa) will be described.

The condensation polymer (c) used in the present invention comprises a repeating unit (a) and a repeating unit (b). The repeating unit (a) is a unit obtained by polycondensing a dicarboxylic acid, a tetracarboxylic acid or a derivative thereof and a diamine, triamine, tetraamine or dihydrazide, and is formed only from the condensed polymer unit (a). The separation membrane (a ′) has a separation coefficient α _a of 7 or more, preferably 7 to 20, more preferably 7 to 10 and 1 ×.
10 ⁻¹⁰ [cm ³ / cm ² · sec · cmHg] or less, preferably 1 × 10 ⁻⁸ to 1 × 10 ⁻¹⁰ [cm ³
/ Cm ² · sec · cmHg] is not particularly limited as long as it has an oxygen permeability coefficient of, for example, amide, hydrazide, imide, isoimide, hydrazide imide, imidazopyrrolone, benzimidazole, benzoxazole, benzothiazole, oxadiene. Condensed polymer units having structural units such as azoles and esters are mentioned, and among them, condensed polymer units having hydrazide imides and imides are preferable. More specifically, the following general formula (a1)

[0015]

[Chemical 15]

[Wherein R ₁ is

[0017]

[Chemical 16]

(Wherein R ₃ is

[0019]

[Chemical 17]

A group represented by any one of the following: ), R ₂ is a group represented by any one of

[0021]

[Chemical 18]

(However, in the formula, R ₄ is

[0023]

[Chemical 19]

A group represented by any one of the following: ) Is a group represented by any one of. ] The hydrazide imide of the repeating unit represented by or the following general formula (a2)

[0025]

[Chemical 20]

An amide having a repeating unit represented by is more preferable.

Further, in the above general formula (a1), R ₁ is the following formula:

[0028]

[Chemical 21]

Is a group represented by and R ₂ is

[0030]

[Chemical formula 22]

A hydrazide imide, which is a group represented by, is more preferable.

The carboxylic acid or its derivative component constituting the repeating unit (a) is not particularly limited as to the dicarboxylic acid, the tetracarboxylic acid, and their derivatives, but among them, an aromatic ring and a heterocyclic ring, respectively. , Having a ring such as alicyclic, dicarboxylic acid, dicarboxylic acid dichloride, dicarboxylic acid diester, tetracarboxylic acid, tetracarboxylic acid dianhydride, tetracarboxylic acid diester, tetracarboxylic acid diester dichloride and the like, respectively, Used alone or in combination of two or more.

Among these carboxylic acids, tetracarboxylic dianhydrides such as pyromellitic dianhydride (hereinafter abbreviated as PMDA), biphenyltetracarboxylic dianhydride, benzophenonetetracarboxylic dianhydride, Diphenyl ether tetracarboxylic dianhydride,
Diphenyl sulfone tetracarboxylic acid dianhydride, hexafluoroisopropylidene diphthalic acid dianhydride, bis (dicarboxyphenyl) methanoic acid dianhydride, bis (dicarboxyphenyl) ethanoic acid dianhydride,

Aromatic such as bis (dicarboxyphenyl) propanoic dianhydride, azobenzenetetracarboxylic dianhydride, naphthalenetetracarboxylic dianhydride, anthracenetetracarboxylic dianhydride, perylenetetracarboxylic dianhydride Tetracarboxylic acid dianhydride; Heterocyclic tetracarboxylic acid dianhydride such as pyridinetetracarboxylic acid dianhydride, thiophenetetracarboxylic acid dianhydride, furantetracarboxylic acid dianhydride; Cyclobutanetetracarboxylic acid dianhydride Cyclopentanetetracarboxylic acid dianhydride, cyclohexanetetracarboxylic acid dianhydride, alicyclic tetracarboxylic acid dianhydrides such as bicyclooctenetetracarboxylic acid dianhydride and the like are preferable, and aromatic tetracarboxylic acid dianhydride is particularly preferable. preferable.

Specific examples of the aromatic tetracarboxylic dianhydride include PMDA, 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride and 3,3', 4,4'-.
Benzophenone tetracarboxylic dianhydride, 3,3 ′,
4,4'-diphenyl ether tetracarboxylic dianhydride, 3,3 ', 4,4'-diphenylsulfone tetracarboxylic dianhydride, 4,4'-(hexafluoroisopropylidene) diphthalic dianhydride (hereinafter , 6FDA), naphthalene-1,2,4,5-tetracarboxylic dianhydride, perylene-3,4,9,10-tetracarboxylic dianhydride, and the like. Among them, 6FDA is excellent. It is most preferable because it provides excellent gas permeation selection characteristics and good dissolution characteristics.

On the other hand, as the diamine, triamine, tetraamine or dihydrazide constituting the repeating unit (a), for example, m-phenylenediamine, 3,5-diaminobenzoic acid, 2,4-diaminophenol, 2,4-
Diaminoanisole, 3,3'-dihydroxybenzidine, 3,3'-diamino-4,4'-dihydroxybiphenyl, 4,4'-diamino-3,3'-dicarboxydiphenylmethane, 2,2-bis (4- (4-aminophenoxy) -3,5-dibromophenyl) propane,
2,2-bis (3-amino-4-hydroxyphenyl)
Hexafluoropropane, 2,7-diaminofluorene, diaminocarbazole, 1,2,4-triaminobenzene, 3,4,4'-triaminobiphenyl ether,

1,2,4,5-tetraaminobenzene,
Amines such as 3,3 ′, 4,4′-tetraaminobiphenyl, phthalic acid dihydrazide, naphthalene dicarboxylic acid dihydrazide, hydroxyisophthalic acid dihydrazide,
Dihydrazide such as dimethyl terephthalic acid dihydrazide, biphenyl dicarboxylic acid dihydrazide, benzophenone dicarboxylic acid dihydrazide, diphenyl ether dicarboxylic acid dihydrazide, diphenyl sulfone dicarboxylic acid dihydrazide, hexafluoroisopropylidene diphthalazide dihydrazide, isophthalic acid dihydrazide, terephthalic acid dihydrate , 6-naphthalenedicarboxylic acid dihydrazide is preferred.

The repeating unit (b) used in the present invention is a unit which imparts mechanical strength without impairing the gas separation characteristics and gas permeability characteristics of the repeating unit (a). The repeating unit (b) is a unit obtained by polycondensing a dicarboxylic acid, a tetracarboxylic acid or a derivative thereof and a diamine or dihydrazide, and the repeating unit (b)
The separation membrane (b ′) formed from only the oxygen / nitrogen separation coefficient α _b and the difference α _a is 2 or less, and the oxygen permeability coefficient is 1 × 10 ⁻¹⁰ [cm ³ / cm ² · sec · cmHg]
Hereinafter, preferably 1 × 10 ⁻⁸ to 1 × 10 ⁻¹⁰ [cm
³ / cm ² · sec · cmHg], and 100 to 30
There is no particular limitation as long as it has a tensile strength of 0 (MPa), but specifically, the following general formula (b1)

[0039]

[Chemical formula 23]

[Wherein R ₅ is

[0041]

[Chemical formula 24]

(However, in the formula, R ₇ is

[0043]

[Chemical 25]

Represents any one of the groups ), R ₆ represents a group represented by any one of

[0045]

[Chemical formula 26]

Represents a group represented by any one of ] It is preferable that it has a hydrazide imide structure or an imide structure represented by any one of
Further, in the general formula (b1), R ₅ is

[0047]

[Chemical 27]

Is a group represented by and R ₆ is

[0049]

[Chemical 28]

More preferred are those which are hydrazide imides or amides which are groups represented by any one of the above.

As the carboxylic acid or its derivative component constituting the repeating unit (b), the same ones as those mentioned in the repeating unit (a) can be mentioned.

On the other hand, the diamine constituting the repeating unit (b), and as the dihydrazide, bis [4- (3-aminophenoxy) phenyl] sulfone, 2,6-naphthalenedicarboxylic acid dihydrazide, trimethylenebis (4-aminobenzoate) ) Or 1,1′-oxybenzidine and the like, among which bis [4- (3-aminophenoxy) phenyl] sulfone and 2,6-naphthalenedicarboxylic acid dihydrazide are preferred.

The condensation type polymer (c) used in the present invention is, for example, a dicarboxylic acid, a tetracarboxylic acid, or a dicarboxylic acid in a suitable solvent such as N-methylpyrrolidone, N, N-dimethylacetamide, dimethylsulfoxide or sulfolane. , A derivative thereof and a diamine, triamine, tetraamine or dihydrazide constituting the repeating unit (a) are polymerized, and then polycondensed with a diamine or dihydrazide constituting the repeating unit (b). At this time, the repeating unit (a) and the repeating unit (b) are mixed with the diamine, triamine, tetraamine or dihydrazide constituting the repeating unit (a) so that the molar ratio becomes 99: 1 to 70:30. The diamine or dihydrazide constituting the unit (b) is converted to 99:
It is preferable to charge at a ratio of 1 to 70:30. When the ratio of the repeating unit (a) to the repeating unit (b) in the condensation polymer (c) is 99: 1 to 70:30 in terms of mol, excellent gas separation characteristics and gas permeation characteristics are maintained. At the same time, it is possible to obtain a separation membrane having excellent workability and tensile strength.

Repeating unit (a) and repeating unit (b)
When each of the amine component and the carboxylic acid component respectively derived from and are subjected to polycondensation, further, if necessary, polyamide, polyimide, a reaction aid used during polymerization of polyhydrazide, etc.,
For example, benzoic acid, pyridine, triethylamine, triphenyl phosphite, tetraethylammonium salt and the like may be added.

The condensation polymer (c) used in the present invention thus produced is 0.5 to 3.0 dL / g, preferably 0.5 to 2.0 dL / g, and more preferably 0.1. 5-
It has an inherent viscosity value of 1.5 dL / g.

The type of the separation membrane of the present invention is not particularly limited, and examples thereof include a homogeneous membrane, a porous membrane, and a heterogeneous membrane (a membrane having a separation active layer composed of a condensed polymer (c) and a support layer). ), A composite membrane (a membrane having a separation active layer composed of a condensed polymer (c) and a support layer composed of a resin having a structural unit different from the resin constituting the active layer), and the like. Homogeneous membranes, heterogeneous membranes, and composite membranes having a separation active layer made of the condensed polymer (c) are preferable because a membrane having excellent substance separation characteristics and substance permeation characteristics can be obtained. The shape of the membrane is arbitrary and may be, for example, a flat membrane, a hollow fiber membrane, a tubular membrane, or a monolith membrane (a tubular membrane having a plurality of core holes).

The separation active layer comprising the condensation type polymer (c) used in the present invention is a resin layer which has a dense surface and is non-porous. Therefore, even if slight pinholes (fine holes) are generated in the layer, even if the resin layer surface is coated or sealed with a material having a high gas permeability such as silicone or polyacetylene, in order to close it. Alternatively, the sealing treatment may be performed with another resin such as a polyimide resin or a polysulfone resin. Further, in order to improve gas selectivity, the resin layer may be subjected to surface treatment such as chlorine or fluorine gas surface treatment, plasma treatment, ultraviolet ray treatment or the like.

The separation membrane of the present invention is particularly useful in the case of gas separation membranes, pervaporation membranes, and other membranes having a resin layer made of a hydrazide imide resin as a separation active layer.
Hereinafter, these will be described by using a gas separation membrane as a representative.

The term "gas separation active layer" as used herein means a substantially non-porous dense layer whose gas permeation mechanism of the membrane is rate-determining the dissolution and diffusion of the gas into the membrane material. The fact that the membrane has a gas separation active layer means that the gas separation coefficient of the membrane is
It can be easily confirmed by matching the original gas separation coefficient of the material forming the gas separation active layer with the original gas separation coefficient within the range of the characteristic variation, regardless of the thickness of the gas separation active layer.

The gas separation membrane preferably has no pinholes and the gas separation active layer is sufficiently thin. There is no limitation on the film shape and the film form, for example, a homogeneous film, a heterogeneous film,
Examples include porous composite membranes. The membrane can be provided as a flat membrane or a hollow fiber membrane, but a hollow fiber membrane that is compact and can obtain a large membrane area is most preferable.

The gas separation characteristics, gas permeation characteristics, and mechanical strength required for these gas separation membranes differ depending on the shape, form, and method of use of the separation membrane in actual use.
Furthermore, even if the same polymer material is used, the strength of the film material cannot be unconditionally specified because it depends on the orientation of the polymer chains depending on the processing method, but for example, the condensation polymer (c In the case where the separation membrane consisting of (4) is a film-like homogeneous membrane of 25 μm, the tensile strength is further increased while maintaining the gas separation characteristics and gas permeation characteristics of the separation membrane (a ′) formed only from the repeating unit (a). Can be improved and is 35 MPa or more, preferably 35 to 100 MP
a, more preferably a tensile strength of 50 to 100 MPa.

The hollow fiber membrane formed from the condensed polymer (c) may be produced by any known method, for example,
The following manufacturing method may be mentioned. The dope of condensation-type polymer (c) (solution for spinning resin) was once introduced into the gas phase from the annular nozzle with a core agent for maintaining the hollow fiber shape and accelerating the porosity of the hollow fiber inner layer. A hollow fiber heterogeneous membrane can be produced by a so-called dry-wet method, in which the dope is extruded and then immersed in a coagulating liquid (a liquid insoluble in the resin and miscible with the organic solvent used for the dope) to coagulate the dope.

Further, for example, the dope (α) of the condensed polymer (c) for forming the resin layer made of the condensed polymer (c) and the polymer dope (β) for forming the support layer.
And are co-extruded into the gas phase in the form of a hollow fiber having a multilayer structure of core, dope (β) and dope (α) in this order from the inside using a multiple ring nozzle, and then immersed in a coagulating liquid to dope. A hollow fiber composite membrane can be produced by coagulating.

The solvent used for the dope may be any solvent which dissolves the condensation type polymer (c) and is compatible with the coagulating liquid, for example, dichloromethane, chloroform, 1,1,2. -Halogenated alkyl solvents such as trichloroethane; halogenated phenolic solvents such as o-chlorophenol, p-chlorophenol, dichlorophenol; N, N-dimethylformamide, N, N
Amide-based solvents such as dimethylacetamide and N-methylpyrrolidone; sulfur-containing solvents such as dimethyl sulfoxide and sulfolane; hexamethylphosphoric triamide, γ-butyrolactone, dioxane, diethylene glycol dimethyl ether, and the like. Used as a mixture of two or more kinds. Among them, N, N
Water-soluble organic solvents such as -dimethylformamide, N, N-dimethylacetamide and N-methylpyrrolidone are preferred.

If necessary, other additive components may be added to the above dope solution for the purpose of improving the stability and spinnability of the dope, and improving the gas selective permeability of the resulting membrane. Is. Other additives include, for example, low molecular weight polymers such as polyethylene glycol, polypropylene glycol, polyvinyl alcohol, and polyvinylpyrrolidone; volatile components such as acetone and tetrahydrofuran; poor solvents such as toluene and xylene; acetic acid,
Acids such as propionic acid and butyric acid; water-soluble polyhydric alcohols such as ethylene glycol and glycerin; inorganic salts such as lithium chloride, lithium bromide, potassium chloride, potassium bromide, calcium chloride and magnesium chloride. .

The fluid used as a core when the dope is extruded into a hollow fiber may be a gas or a liquid, for example, a gas such as nitrogen or air; water, methanol, ethanol, propanol, glycerin, or a mixture thereof. A liquid such as a liquid can be used. In addition, if necessary, these core materials may be added to inorganic salts such as lithium chloride, lithium bromide, potassium chloride; N-methylpyrrolidone, N, N
A solvent for the resin such as dimethylacetamide; acetone,
A poor solvent for the dope resin such as methyl ethyl ketone, xylene, toluene, acetic acid, and propionic acid can be appropriately added.

The atmosphere for extruding the dope may be a gas phase such as an air atmosphere, a nitrogen atmosphere, a vapor atmosphere of a solvent or the like, or a liquid phase such as water, but it is preferably a gas phase. preferable. As for the atmosphere, the air flow can be appropriately adjusted, and the temperature, the humidity and the like can be adjusted as necessary.

The dope having a single-layer or multi-layer structure extruded in the shape of a hollow fiber from the multi-annular nozzle is solidified by contact with a coagulating liquid. As the coagulating liquid, any liquid can be used as long as the resin forming the hollow fiber membrane is insoluble and can be mixed with the solvent used for the dope. For example, lower alcohols such as methanol, ethanol, 1-propanol, 2-propanol; aldehydes or ketones such as acetaldehyde, acetone; water or a mixed liquid thereof can be used. The coagulating liquid may contain a substance such as an organic solvent, salt, acid or alkali, and among them, water or a mixed liquid of water and another organic solvent is preferable.

When the separation membrane of the present invention is a composite membrane, that is, when the material constituting the resin layer comprising the condensed polymer (c) and the material constituting the support layer are different, the material for the support layer is arbitrary. If the resin has sufficient mechanical strength, heat resistance, chemical resistance, weather resistance, etc. that can sufficiently adhere to the resin layer composed of the condensation polymer (c) and can withstand the actual use of the film The resin may be a resin having a structural unit other than the polymer (c), and may be a mixture or copolymer of one or more kinds.

Preferred resins for forming the support layer are, for example, polyamide resins, polyimide resins, polyetherimide resins, polyamideimide resins, polysulfone resins, polybenzimidazole resins, polybenzoxazole resins. , Polybenzothiazole-based resins, polyquinoxalin-based resins, polypiperazine-based resins, and the like, and these can be used alone or in combination of two or more. Examples of the polysulfone-based resin include
It is marketed as polysulfone, polyether sulfone, polyallyl sulfone, and polyphenyl sulfone.

In the hollow fiber heterogeneous membrane, for example, the dope composition, concentration, temperature, coagulation liquid composition, inner tube fluid composition, spinning conditions, etc. are appropriately selected. By changing the order of the dope (α) and the dope (β) from the core agent side, the resin layer composed of the condensed polymer (c) can be formed on either the inner surface or the outer surface of the hollow fiber. is there. Among these, a composite membrane in which a dense layer is formed on the outer surface of the hollow fiber is preferable because it is excellent in mass productivity and gas permeation selection characteristics of the obtained membrane. The dimensions of the hollow fiber membrane are arbitrary and can be appropriately adjusted to an outer diameter, an inner diameter and the like suitable for practical use. Specifically, composition of dope, concentration, temperature, composition of coagulating liquid, composition of inner tube fluid, spinning condition (extrusion speed of dope, winding speed of formed hollow fiber, etc.)
It is possible to manufacture a hollow fiber having an outer diameter of 1500 μm or less and a film thickness of 500 μm or less by controlling the above conditions.

It is preferable that the organic solvent remaining in the film obtained as described above is substantially removed. For example, the organic solvent is removed by washing with warm water, a low-boiling solvent capable of dissolving the residual solvent, for example, isopropyl alcohol. It can be carried out by a known method such as performing vacuum heating drying after washing and replacing with (IPA), methanol, ethanol and the like.

In the method for producing the separation membrane of the present invention, the precursor of the condensation type polymer (c) is used as the resin layer forming dope of the condensation type polymer (c), and the same method as the above-mentioned production method is used. A method for producing a film having a resin layer composed of a precursor of the condensation polymer (c) and subjecting it to heat treatment to change the precursor of the condensation polymer (c) into an intended structure is described. It can also be adopted.

This method is particularly useful when the condensation type polymer (c) is insoluble or hardly soluble in an organic solvent and cannot form a dope. The repeating unit (a) and the repeating unit (b) are simultaneously heated to be converted into the final target structure.

The heat treatment conditions are such that the resin layer of the precursor substantially changes into the desired chemical structure, and preferably both repeating units (a) and (b) change into the final desired structure. And in the case of a composite membrane, it is sufficient if the porous structure of the polymer forming the support layer is not destroyed by heating, and for example, under reduced pressure and / or an inert gas atmosphere, 150 to 450 ° C., preferably Is 150-350 ° C
Then, it may be 20 to 720 minutes, preferably 20 to 480 minutes. The term "under reduced pressure" as used herein means that the resin constituting the film is not affected by oxidative deterioration during the heat treatment, and examples thereof include a reduced pressure atmosphere of 30 kPa or less, preferably 3 kPa or less. Preferable examples of the inert gas include nitrogen, argon and helium. A reduced pressure inert gas atmosphere is also preferable.

The change from the precursor to the final desired chemical structure due to the heat treatment can be easily confirmed by the infrared absorption spectrum. For example, if a change to a hydrazide imidization from the precursor, about 1700~1780cm a characteristic absorption band region and 1790～1800Cm ^-1 near the imide ring of ^-1, characteristic absorption bands of amide bond in the vicinity of 1690 cm ^-1 Can be easily confirmed by the simultaneous recognition of.

In the present production method, it is preferable that the removal of the organic solvent for dope is carried out before the heat treatment step for changing the chemical structure to the final purpose.

The separation membrane of the present invention is, for example, oxygen / air /
Nitrogen separation, separation and recovery of hydrogen from off-gas of platforming method, recovery of hydrogen during ammonia synthesis, recovery of carbon dioxide from waste gas of thermal power generation and refuse incineration, removal of nitrogen oxides and sulfur oxides, oil field Recovery of carbon dioxide from off-gas, removal of hydrogen sulfide from natural gas, acid gas such as carbon dioxide, removal of carbon dioxide from landfill gas and gas separation such as helium separation, dehumidification of air and organic vapor, etc. Gas-steam or steam-steam separation, further separation of water and alcohol, pervaporation separation of volatile substance mixed liquid such as water removal from esterification reaction system, removal of gas dissolved in liquid, It is preferably used for dissolving a specific gas in a liquid. Needless to say, the use of the separation membrane of the present invention is not limited to these.

[0079]

EXAMPLES The present invention will be described in more detail with reference to Examples and Comparative Examples below. Example 1 18.448 g (0.095 mol) of isophthalic acid dihydrazide (IPDH) at room temperature under a nitrogen atmosphere.
And bis [4- (3-aminophenoxy) phenyl] sulfone (BAPS-M) 2.1625 g (0.005).
Dimethyl sulfoxide (DMS)
O) in 350 g, and then the solution of tetracarboxylic acids 4,4 ′-(hexafluoroisopropylidene) diphthalic acid dianhydride (6FDA) 44.42 was added to the solution.
4 g (0.1 mol) was added in several portions as a solid. The viscosity of this solution increased with the progress of the polymerization reaction, and the reaction was continued by stirring for 4 hours. The obtained reaction solution was added dropwise to a large amount of 2-propanol, and after stirring well, the precipitate was washed several times with a large amount of water, roughly dried with hot air at 100 ° C, and then vacuum dried at 100 ° C. As a result, a precursor polymer was obtained. This solid was heat-treated under vacuum at 250 ° C. for 8 hours to obtain a thermally closed hydrazide imide copolymer solid.

A part of the obtained hydrazide imide copolymer was dissolved in NMP so that the concentration was 1.0% by weight, and the dropping time of the solution was measured at 30 ° C. using an Ostwald viscometer to measure NMP. The specific viscosity with respect to the viscosity of was calculated. The results are shown in Table 1.

A part of the obtained hydrazide imide type copolymer was dissolved in N-methylpyrrolidone (NMP) so that the concentration was 20% by weight, and then cast on a glass plate to obtain 10 parts.
After being dried at 0 ° C. and solidified into a film, vacuum drying was carried out at 250 ° C. for 8 hours to obtain a film-like homogeneous film having a thickness of 25 μm and made of a hydrazide imide copolymer. The oxygen and nitrogen gas permeation coefficients of the obtained homogeneous membrane were measured in accordance with ASTM D1434 under conditions of 25 ° C. atmosphere and pressure difference of 0.2 MPa using pure gas, respectively, and the oxygen / nitrogen separation coefficient was calculated. . The results are shown in Table 1.

From the obtained homogeneous film, 10 mm × 15
Cut out a 0 mm rectangular test piece (type 2) and
The tensile strength was measured at a speed of 50 mm / min based on IS K7127, and the results are shown in Table 1.

Since the gas separation coefficient of the membrane matches the original separation coefficient of the material forming the gas separation active layer within the range of the characteristic variation, regardless of the thickness of the gas separation active layer, the above hydrazide is used. It can be seen that the gas separation coefficient of the composite membrane having a non-porous and dense thin layer made of an imide-based copolymer as the gas separation active layer also substantially matches the gas separation coefficient of the homogeneous membrane. This also applies to the following examples.

(Example 2) 18.934 g of IPDH
(0.0975 mol), 1.0812 g of BAPS-M
The specific viscosity was calculated in the same manner as in Example 1 except that (0.0025 mol) was used to obtain a film-like homogeneous film having a thickness of 25 μm and made of a hydrazide imide-based copolymer.
By the same method, the gas permeability coefficient of oxygen and nitrogen was measured, the separation coefficient of oxygen / nitrogen was calculated, and the tensile strength was measured. The results are shown in Table 1.

Example 3 Instead of BAPS-M, 2,
6-Naphthalenedicarboxylic acid dihydrazide (NDH)
The specific viscosity was calculated in the same manner as in Example 1 except that 1.221 g (0.005 mol) was used to obtain a film-like homogeneous film having a thickness of 25 μm and made of a hydrazide imide-based copolymer. By the same method, the gas permeability coefficient of oxygen and nitrogen was measured, the separation coefficient of oxygen / nitrogen was calculated, and the tensile strength was measured. The results are shown in Table 1.

Example 4 At room temperature under a nitrogen atmosphere,
3'-dihydroxybenzidine (DHBZ) 10.17
8 g (0.0475 mol) and IPDH 9.225 g
(0.0475 mol) was dissolved in 500 g of dehydrated NMP, 300 g of sulfolane was added to this solution, and after homogenization, 44.424 g (0.1 mol)
6FDA was added as a solid in several portions. As the polymerization reaction progressed, this solution was gradually homogenized, and after visually confirming that it became almost transparent, 2.1625 g
(0.05 mol) of BAPS-M was added, and 1 was added as it was.
The reaction was allowed to stir for a period of time. A large amount of the obtained reaction solution
-Imidazopyrrolone-hydrazide imide-imide co-polymer which was added dropwise to propanol and the precipitated solid was washed several times with a large amount of water, then thoroughly replaced with 2-propanol and vacuum dried at 100 ° C to purify. A combined precursor polymer was obtained.

A part of the obtained precursor polymer of the imidazopyrrolone-hydrazide imide-imide copolymer was dissolved in NMP so that the concentration was 1.0% by weight, and the solution was dissolved at 30 ° C. using an Ostwald viscometer. Of the dropping time of N
The specific viscosity with respect to the viscosity of MP was calculated. The results are shown in Table 1.

A part of the obtained precursor polymer of the imidazopyrrolone-hydrazide imide-imide copolymer was dissolved in NMP so that the concentration was 12.5% by weight, and then cast on a glass plate at 100 ° C. After being dried in a solid form into a film, the film was vacuum dried at 320 ° C. for 8 hours to obtain a film-like homogeneous film having a thickness of 25 μm and made of an imide copolymer. Next, the gas permeability coefficient of oxygen and nitrogen was measured, the separation coefficient of oxygen / nitrogen was calculated, and the tensile strength was measured by the same method. The results are shown in Table 1.

Comparative Example 1 19.419 g of isophthalic acid dihydrazide as dihydrazide at room temperature under nitrogen atmosphere
(0.1 mol) was suspended in 350 g of dehydrated NMP, and then 44.424 g (0.1 mol) of 6FDA was added as a solid to this solution in several portions. As the polymerization reaction proceeded, the solution was gradually homogenized and visually confirmed to be almost transparent, and then 24.424 g (0.2 mol) of benzoic acid was added as a reaction aid. After stirring for 1 hour as it is to react, pyridine (15.820 g, 0.2 mol) was further added as a reaction aid, and 1
The reaction was continued by stirring for a period of time. The obtained reaction solution was added dropwise to a large amount of water, and the precipitated solid was washed with a large amount of water several times,
After rough drying with hot air at 100 ° C, vacuum drying was performed at 100 ° C to obtain a precursor polymer of polyhydrazide imide. This solid was heat-treated at 250 ° C. for 8 hours underneath to obtain a heat-closed polyhydrazide imide solid.

A part of the obtained hydrazide imide copolymer was dissolved in NMP so that the concentration was 1.0% by weight, and the dropping time of the solution was measured at 30 ° C. using an Ostwald viscometer to measure NMP. The specific viscosity with respect to the viscosity of was calculated. The results are shown in Table 1.

Part of the obtained polyhydrazide imide was dissolved in NMP to a concentration of 20% by weight, then cast on a glass plate, dried at 100 ° C. to solidify into a film, and then 250 Vacuum drying was performed at 8 ° C. for 8 hours to obtain a film-like homogeneous film made of polyhydrazide imide and having a thickness of 25 μm. Next, the gas permeability coefficient of oxygen and nitrogen was measured, the separation coefficient of oxygen / nitrogen was calculated, and the tensile strength was measured by the same method. The results are shown in Table 1.

This polyhydrazide imide was prepared according to Example 1,
2 and 3 of BAPS-M or NDH-free homopolymer. As shown in Table 1, Examples 1, 2 and 3
Of the gas separation characteristics of Comparative Example 1 are almost equal to or higher than those of Comparative Example 1, and it is clear that the copolymerization with BAPS-M or NDH does not cause the deterioration of the separation characteristics of Examples 1, 2 and 3. .

The polymer of Comparative Example 1 had a specific viscosity of 0.4.
3. Tensile strength of the membrane is 13 MPa, and the polymer of this degree has no problem in preparing a film-like homogeneous membrane and performing gas permeation measurement, but it is a non-homogeneous membrane or a hollow fiber homogeneous membrane. When preparing a film having such a structure, the strength of the material itself will be reduced, so suitable processing conditions,
The range of usage conditions becomes very narrow. On the other hand, in Examples 1 to 3, by copolymerizing BAPS-M or NDH, the specific viscosity and the tensile strength of the film were significantly increased. And, the durability is also improved.

Comparative Example 2 43.
249 g (0.1 mol) of BAPS-M was dissolved in 350 g of dehydrated NMP, and then 44.
424 g (0.1 mol) of 6FDA was added as a solid in portions. With the progress of the polymerization reaction, this solution was gradually homogenized, and the reaction was continued while stirring for 4 hours. Subsequently, after adding 300 g of NMP to dilute the reaction solution, 31.640 g of pyridine and 40.836 g of acetic anhydride were added as reaction aids, stirred for 1 hour, then heated to 55 ° C. and stirred for 1 hour. It was made to react. Or later,
The specific viscosity was calculated in the same manner as in Example 4, and a uniform film-like homogeneous film made of polyimide and having a thickness of 25 μm was obtained. Then, the gas permeation coefficient of oxygen and nitrogen was measured by the same method. / The separation coefficient of nitrogen was calculated and the tensile strength was measured. The results are shown in Table 1.

This polyimide is a homopolymer consisting only of 6FDA and BAPS-M of the repeating unit (b) of Examples 1, 2 and 4. As shown in Table 1, it is clear that the gas separation property of this polyimide is inferior to that of Comparative Example 1, and nevertheless, Examples 1, 2 and 4 were used.
Has a high gas separation property.

(Comparative example 3) 24.
Dehydrated 425 g (0.1 mol) of NDH 350
g of NMP, then add 44.42 to this solution.
4 g (0.1 mol) of 6FDA was added as a solid in portions. Subsequently, it was heated to 50 ° C., and it was visually confirmed that the reaction solution was gradually homogenized and became almost transparent as the polymerization reaction proceeded, and then the reaction was continued by stirring at room temperature for 3 hours. The obtained reaction solution was added dropwise to a large amount of 2-propanol, and the precipitated solid was washed with a large amount of water several times.
After sufficiently substituting with propanol, the precursor polymer of polyhydrazide imide was obtained by vacuum drying at 100 ° C.

A part of the obtained hydrazide imide type copolymer was dissolved in NMP so that the concentration was 1.0% by weight, and the dropping time of the solution was measured at 30 ° C. using an Ostwald viscometer to measure NMP. The specific viscosity with respect to the viscosity of was calculated. The results are shown in Table 1.

A part of the obtained polyhydrazide imide precursor polymer was dissolved in NMP to a concentration of 20% by weight, then cast on a glass plate and dried at 100 ° C. to solidify into a film. After that, vacuum drying was performed at 250 ° C. for 8 hours to obtain a film-like homogeneous film made of polyhydrazide imide and having a thickness of 25 μm. Next, the gas permeability coefficient of oxygen and nitrogen was measured, the separation coefficient of oxygen / nitrogen was calculated, and the tensile strength was measured by the same method. The results are shown in Table 1.
Shown in.

This polyhydrazide imide is a homopolyhydrazide imide consisting only of 6FDA and NDH of the repeating unit (b) of Example 3. As shown in Table 1, it is clear that the gas separation property of this polyhydrazide imide is inferior to that of Comparative Example 1, and nevertheless, Example 3 has a high gas separation property. I understand.

(Comparative Example 4) At room temperature under nitrogen atmosphere,
3'-dihydroxybenzidine (DHBZ) 10.71
4 g (0.05 mol) and IPDH 9.710 g (0.0
(5 mol) is dissolved in 500 g of dehydrated NMP, and then 300 g of sulfolane is added to this solution, and after homogenization, 44.424 g (0.1 mol) of 6FDA is added in several steps as a solid. did. As the polymerization reaction proceeded, the solution was gradually homogenized and visually confirmed to be almost transparent, and then stirred for 1 hour to be reacted. The obtained reaction solution was added dropwise to a large amount of 2-propanol, the precipitated solid matter was washed several times with a large amount of water, and then,
A precursor polymer of a purified imidazopyrrolone-hydrazide imide copolymer was obtained by thoroughly substituting with 2-propanol and vacuum drying at 100 ° C.

A part of the resulting precursor polymer of the imidazopyrrolone-hydrazide imide copolymer was dissolved in NMP so that the concentration was 1.0% by weight, and the solution was added dropwise at 30 ° C. using an Ostwald viscometer. The time was measured, and the specific viscosity with respect to the viscosity of NMP was calculated. The results are shown in Table 1.

A part of the obtained precursor polymer of the imidazopyrrolone-hydrazide imide copolymer was added at a concentration of 12.5.
It is dissolved in NMP so as to have a weight percentage, then cast on a glass plate, dried at 100 ° C. to solidify into a film, and then vacuum dried at 320 ° C. for 8 hours to form an imide copolymer. A film-like homogeneous film having a thickness of 25 μm was obtained.
Next, the gas permeability coefficient of oxygen and nitrogen was measured, the separation coefficient of oxygen / nitrogen was calculated, and the tensile strength was measured by the same method. The results are shown in Table 1.

This polyimide is the BAPS-based product of Example 4.
It is a copolymer containing no M. As shown in Table 1, the characteristic of Example 4 and the characteristic of Comparative Example 4 show almost the same gas separation characteristics, and that the characteristic of Example 4 is not affected by the copolymerization with BAPS-M. It's obvious.

The polymer of Comparative Example 4 had a specific viscosity of 0.5.
8. The tensile strength of the membrane is 34 MPa, and the polymer of this degree has no problem in preparing a film-like homogeneous membrane and performing gas permeation measurement, but it is a heterogeneous membrane or a hollow fiber homogeneous membrane. When preparing a film having such a structure, the strength of the material itself will be reduced, so suitable processing conditions,
The range of usage conditions becomes very narrow. On the other hand, in Example 4, by copolymerizing BAPS-M, since the specific viscosity and the tensile strength of the film are greatly increased, the molecular weight is sufficiently high, and thus the processability is naturally improved, and , Durability is also improved.

(Comparative Example 5) 15.717 g of trimethylenebis (4-aminobenzoate) as a diamine component
The specific viscosity was calculated in the same manner as in Example 1 except that (0.05 mol) was used.
A uniform film having a uniform thickness of μm was obtained, and then the gas permeability coefficient of oxygen and nitrogen was measured, the separation coefficient of oxygen / nitrogen was calculated, and the tensile strength was measured by the same method.
The results are shown in Table 1.

This polyimide is the BA of Examples 1 and 3.
Instead of PS-M or NDH, trimethylenebis (4
-Aminobenzoate) is a hydrazide imide-based copolymer. As shown in Table 1, the gas separation characteristics of Comparative Example 5 are clearly lower than those of Examples 1 and 3. The gas permeation separation characteristics of the polyimide consisting only of 6FDA and trimethylene bis (4-aminobenzoate) have an oxygen permeation coefficient of 0.537 barrer and an oxygen / nitrogen separation coefficient of 5.91, indicating the significance of Examples 1 to 4. To be done.

Comparative Example 6 12.622 g (0.06) of isophthalic acid dihydrazide (IPDH) in Example 1
5 mol) and 15.1375 g of bis [4- (3-aminophenoxy) phenyl] sulphone (BAPS-M).
A solid product of a hydrazide imide-based copolymer was obtained in the same manner except that (0.035 mol) was used. Each test was conducted in the same manner as in Example 1. The results are shown in Table 1. When the structure derived from BAPS-M in the copolymer exceeds 30 mol%,
The separation factor was clearly lower than in Examples 1 and 2.

[0108]

[Table 1]

Example 5 As a spinning dope (α),
The hydrazide imide-based copolymer obtained in Example 1 / lithium chloride / NMP = 20/5/80 (weight conversion) was dissolved and the filtration pore size was 20 μm while keeping the temperature at about 60 ° C.
The solution prepared by filtering with a stainless steel filter of No. 2 and defoaming under reduced pressure was used. In addition, polyamide (Teijin Conex) / lithium chloride / NMP = 2
It was dissolved in a ratio of 0/5/75 (weight conversion), filtered with a stainless filter having a filtration pore size of 20 μm while keeping the temperature at about 60 ° C., and further defoamed under reduced pressure to obtain a dope for spinning (β).

From the outer diameter of the circular pipe, φ1.8-φ1.5-φ1.
Using a multi-annular nozzle of 1-φ0.4-φ0.2 (mm), while letting water flow from the central circular tube, the dope (β) is discharged from the inner circular tube at a discharge rate of about 3 g / min, About 0.6 g / mi of dope (α) heated to about 70 ° C from the outer circular tube
After being simultaneously discharged into the air atmosphere at a discharge amount of n, it is continuously introduced and solidified in water adjusted to 5 ° C.
It was wound on a bobbin at a winding speed of m / min. The obtained hollow fiber was dipped in running water at about 50 ° C., thoroughly washed, dried with water, and further vacuum dried at about 100 ° C. Then, heat treatment was performed in vacuum at 250 ° C. for 8 hours.

The obtained hollow fiber composite membrane had an inner diameter of about 240 μm.
m, the outer diameter is about 480 μm, and the ratio of the thickness of the support layer inside the hollow fiber to the thickness of the gas separation active layer made of the hydrazide imide copolymer outside the hollow fiber is about 6 by microscopic observation of the hollow fiber cross section. The gas separation active layer made of a hydrazide imide copolymer on the outside of the hollow fiber forms a dense layer formed on the outer surface of the hollow fiber, and the dense layer is supported by a support layer made of a porous layer. It was confirmed to have. The gas permeation characteristics of oxygen and nitrogen of the obtained hollow fiber composite membrane were measured by using pure gas and pressurizing the inside of the hollow fiber according to ASTM D1434 in a 25 ° C. atmosphere and a pressure difference of 0.2 MPa. The separation factor of nitrogen was calculated. The results are shown in Table 2.

Example 6 A hollow fiber composite was prepared in the same manner as in Example 10, except that polyimide (Teijin Conex) and polyimide (Ciba-Geigy matrimid 5218) were used as the spinning dope (β). Membranes were obtained and then oxygen and nitrogen gas permeation properties were similarly measured. The results are shown in Table 2.

Example 7 A polyimide varnish (Rikacoat SN20 manufactured by Shin Nippon Rika) / lithium chloride = 95/5 was used in place of the NMP solution of polyamide (Conex made by Teijin) containing lithium chloride as a dope (β) for spinning. A hollow fiber composite membrane was obtained in the same manner as in Example 10 except that it was used, and then the gas permeation characteristics of oxygen and nitrogen were measured.
The results are shown in Table 2.

(Example 8) NM of polyimide (matrimide 5218 manufactured by Ciba-Geigy) as a dope (β) for spinning
Matrimide 5218 / polyetherimide (GE plastic Ultem 1000) / NMP instead of P solution
A hollow fiber composite membrane was obtained in the same manner as in Example 10 except that a resin solution dissolved in a ratio of = 17.5 / 7.5 / 75 (converted to weight) was used. And the gas permeation characteristics of nitrogen were measured. The results are shown in Table 2.

(Example 9) NM of polyimide (matrimide 5218 manufactured by Ciba-Geigy) as a dope (β) for spinning
Matrimide 5218 / Polyethersulfone (Teijin Amoco Radel A100) / NMP instead of P solution
A hollow fiber composite membrane was obtained in the same manner as in Example 10 except that a resin solution dissolved in a ratio of 20/5/75 (in terms of weight) was used, and then a gas of oxygen and nitrogen was similarly obtained. The transmission characteristics were measured. The results are shown in Table 2.

(Example 10) As the spinning dope (α), the polyhydrazide imide resin obtained in Example 2 was used in place of the polyhydrazide imide resin obtained in Example 1, NMP of polyimide (matrimide 5218 manufactured by Ciba-Geigy) as a dope (β)
Example 1 except that a resin solution dissolved in a ratio of matrimide 5218 / polybenzimidazole / NMP = 10/15/75 (weight conversion) was used instead of the solution.
A hollow fiber composite membrane was obtained in the same manner as in Example 0, and the gas permeation characteristics of oxygen and nitrogen were measured. The results are shown in Table 2.

(Example 11) As the spinning dope (α), the polyhydrazide imide resin obtained in Example 3 was used in place of the polyhydrazide imide resin obtained in Example 1, NMP of polyimide (matrimide 5218 manufactured by Ciba-Geigy) as a dope (β)
Instead of solution, Matrimid 5218 / polyetherimide (GE plastic Ultem 1000) / NMP
A hollow fiber composite membrane was obtained in the same manner as in Example 10 except that a resin solution dissolved at a ratio of = 17.5 / 7.5 / 75 (weight conversion) was used, and gas permeation of oxygen and nitrogen was obtained. The properties were measured. The results are shown in Table 2.

(Example 12) As the spinning dope (α), the polyhydrazide imide resin precursor polymer obtained in Example 7 was used in place of the polyhydrazide imide resin obtained in Example 1. As a dope (β) for spinning, instead of the NMP solution of polyimide (Matrimid 5218 manufactured by Ciba-Geigy), Matrimid 521 was used.
Example 1 except that a resin solution dissolved in a ratio of 8 / Ricacoat SN20 = 15/85 (weight conversion) was used.
A hollow fiber composite membrane was obtained in the same manner as in 0. Further, heat treatment was carried out in vacuum at 350 ° C. for 4 hours to convert the amide amino acid body component as the copolymerization component into imidazopyrrolone. Next, the gas permeability characteristics of oxygen and nitrogen were measured. The results are shown in Table 2.
Shown in.

Example 13 As the dope (α) for spinning, the polyhydrazide imide resin obtained in Example 9 was used in place of the polyhydrazide imide resin obtained in Example 1, NMP of polyimide (matrimide 5218 manufactured by Ciba-Geigy) as a dope (β)
A hollow fiber composite membrane was obtained in the same manner as in Example 10 except that the same resin solution as in Example 11 was used instead of the solution, and the gas permeation characteristics of oxygen and nitrogen were measured. The results are shown in Table 2.
Shown in.

[0120]

[Table 2]

[0121]

Effect of the Invention] The present invention, separation factor oxygen / nitrogen of at least 7, the oxygen permeability coefficient of ^{1 × 10 -1 0 [cm 3} / cm
It is possible to provide a separation membrane having excellent workability and excellent mechanical strength, particularly tensile strength while maintaining excellent gas separation performance of ² sec / cmHg or less.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) B01D 71/66 B01D 71/66 71/68 71/68 C08G 73/06 C08G 73/06 C08J 5/18 CFG C08J 5/18 CFG C08L 79/04 C08L 79/04 F term (reference) 4D006 GA25 GA41 MA01 MA02 MA03 MA04 MA06 MB03 MB04 MC54X MC57 MC58X MC59 MC62 NA04 NA12 NA13 NA51 NA63 PA01 PB17 PB62 PB63 PC71 4F071 AA60 AF02 AF15 A02 AF02 AF15 A02 AF02 AF15 A02 BC02 4J002 CM031 CM041 GD05 4J043 PA04 QB31 QB32 QB33 QB36 QB38 QB39 QB41 RA01 RA08 RA15 RA33 RA35 RA37 SA06 SA07 SA08 SA39 SA53 SA54 SA71 SA81 TA22 TA23 TA32.

Claims (10)

[Claims] 1. A separation membrane formed from a condensed polymer (c) comprising a repeating unit (a) and a repeating unit (b), wherein the repeating unit (a) is a dicarboxylic acid, a tetracarboxylic acid or a compound thereof. Derivative of diamine, triamine,
A separation membrane (a ′) which is a unit obtained by polycondensation with tetraamine or dihydrazide and is formed only from the unit (a) has an oxygen / nitrogen separation coefficient α _a 7 or more and an oxygen permeability coefficient of 1 ×. 10 ⁻¹⁰ [cm ³ / cm ² · sec · cm
Hg] or less, wherein the repeating unit (b) is a unit obtained by polycondensing a dicarboxylic acid, a tetracarboxylic acid or a derivative thereof and a diamine or dihydrazide, and the unit (b)
The separation membrane (b ′) formed from only the oxygen / nitrogen separation coefficient α _b is less than 2 from α _a, and the oxygen permeability coefficient is 1 × 1.
The tensile strength is 0 to ¹⁰ [cm ³ / cm ² · sec · cmHg] or less, the tensile strength is 100 to 300 (MPa), and the molar ratio of the repeating unit (a) to the repeating unit (b) is 99: 1 to 70:30, an oxygen / nitrogen separation factor of 7 or more, and 35 to 100 (MPa)
A separation membrane having the following tensile strength. 2. The condensation polymer (c) has a concentration of 0.5 to 3.0.
The separation membrane according to claim 1, which has an inherent viscosity value of dL / g. 3. The separation membrane according to claim 1, wherein the repeating unit (a) is hydrazide imide or imide. 4. A hydrazide imide is represented by the following general formula (a1): [However, in the formula, R ₁ is (In the formula, R ₃ is Is a group represented by any one of ), R ₂ is (However, in the formula, R ₄ is Is a group represented by any one of ) Is a group represented by any one of. ] The separation membrane of Claim 3 which is a repeating unit represented by these. 5. In the general formula (a1), R ₁ is represented by the following formula: Is a group represented by and R ₂ is The separation membrane according to claim 4, which is a group represented by: 6. The imide is represented by the following general formula (a2): The separation membrane according to claim 3, which is a repeating unit represented by: 7. The repeating unit (b) is represented by the following general formula (b
1) [Chemical 9] [However, in the formula, R ₅ is (However, in the formula, R ₇ is Represents any one of the groups. ), R ₆ is a group represented by the following formula: Represents a group represented by any one of ] The separation membrane as described in any one of Claims 1-6 which has a repeating unit represented by any one of these. 8. In the general formula (b1), R ₅ is And R ₆ is a group represented by The separation membrane according to claim 7, which is a group represented by any one of the following. 9. A separation polymer (c) comprising the repeating unit (a) and the repeating unit (b) according to any one of claims 1 to 8 and having 7 or more oxygen / nitrogen separations. A separation active layer having a coefficient and a tensile strength of 35 to 100 (MPa), and a polyamide resin, a polyimide resin, a polyetherimide resin, a polyamideimide resin, a polysulfone resin, a polybenzimidazole resin One or more resins selected from the group consisting of a polybenzoxazole-based resin, a polybenzothiazole-based resin, a polyquinoxaline-based resin, and a polypiperazine-based resin, the resin (d) having a different type from the resin layer. A separation membrane having a formed support layer. 10. The separation membrane is a gas separation membrane.
9. The separation membrane according to any one of 9 above.