JP3440730B2 - Aromatic polyimide, semipermeable membrane and method for producing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

The present invention relates to an aromatic polyimide having an ammonium sulfonate group in a polyimide skeleton, which uses a diamine having an ammonium sulfonate group as a copolymerization component, a method for producing the same, an aromatic polyimide semipermeable membrane and the same. Regarding manufacturing method.

[0002]

Aromatic polyimides are, for example, films,
As sheets, molded products, hollow fibers, varnishes, etc., they are industrially used in large quantities in the fields of electronic materials, electrical insulation, gas separation, medical care and the like. Aromatic polyimide is generally polycondensed in the organic solvent approximately equimolar amounts of aromatic tetracarboxylic dianhydride such as pyromellitic dianhydride and aromatic diamine such as diaminodiphenyl ether to polyamic acid, It is then prepared by a two-step polymerization process in which the polyamic acid is imidized with heating or in an acid anhydride such as acetic anhydride.

Recently, a polyimide having a polyimide skeleton containing a sulfonic acid group, an alkali sulfonate group, an ammonium sulfonate group, etc. has been reported. For example, in JP-A-6-87957, an aromatic tetracarboxylic acid, an aromatic diamine having an ammonium sulfonate group, and an aromatic diamine having no ammonium sulfonate group are referred to as N-methylpyrrolidone. Copolyimides produced by a two-stage polymerization method of polycondensation to polyamic acid in various organic solvents, and then imidization (chemical imidization) in triethylamine and acid anhydride, and a production method thereof. The publication does not disclose a one-step polymerization method of an aromatic polyimide having an ammonium sulfonate group. Further, although there is a description including an extremely wide range of tetracarboxylic acids as a general formula of aromatic tetracarboxylic acid, there is no specific description about biphenyltetracarboxylic dianhydride.

Japanese Unexamined Patent Publication (Kokai) No. 5-192552 discloses an aromatic polyimide gas separation membrane composed of an aromatic tetracarboxylic acid and a copolyimide having bisphenylfluorenediamine having a sulfonic acid group as a diamine as a copolymerization component. ing. In the examples of the publication, N is used as a solvent.
Disclosed is a homogeneous membrane in which methylpyrrolidone is used and benzophenonetetracarboxylic acid and bisphenylfluorenediamine having a sulfonic acid group as a diamine are used as copolymerization components. JP-A-63-283704
JP-A-63-283707 discloses a copolyimide having pyromellitic dianhydride as an aromatic tetracarboxylic acid and diaminobenzenesulfonic acid having an alkali metal sulfonate as a diamine as a copolymerization component. Homogeneous membranes such as selective permeable membranes and amphoteric polyelectrolyte separation membranes are disclosed. JP-A-58-153541 uses N-methylpyrrolidone as a solvent,
An ion-exchange membrane of polyimide obtained from an aliphatic dianhydride and a diamine having a sulfonic acid group or an alkali sulfonate group is disclosed.

Introducing a highly polar sulfonic acid group, alkali metal sulfonate group, ammonium sulfonate group or the like into the polyimide skeleton generally improves gas permeability, selectivity and the like. Further, in order to practically use polyimide as a gas separation membrane having high practical efficiency, it is most desirable to use it as an asymmetric hollow fiber membrane. However, polyimides having these groups, which have been conventionally disclosed and proposed, do not have sufficient spinnability and film-forming properties and cannot be formed into hollow fiber membranes, or a technique for forming hollow fiber membranes has not been established, or hollow fiber membranes have not been established. Even if it could be realized, there were problems that the mechanical strength of the membrane was inferior, gas permeability and selectivity were not sufficient.

[0006]

DISCLOSURE OF THE INVENTION The present invention has a fragrance which is excellent in gas permeability and selectivity, and is capable of easily forming a high-strength asymmetric hollow fiber membrane, and is excellent in spinnability and film-forming property. It is intended to provide a group polyimide and an aromatic polyimide semipermeable membrane. Further, the present invention has an excellent ability to spin gas, which has excellent gas permeability and selectivity, and can easily form a high-strength asymmetric hollow fiber membrane. It is an object of the present invention to provide a method for producing an aromatic polyimide and a method for producing an aromatic polyimide semipermeable membrane.

The present inventors have diligently studied an aromatic polyimide having an ammonium sulfonate group or the like. As a result, using an aromatic tetracarboxylic dianhydride containing biphenyltetracarboxylic dianhydride as a main component and an aromatic diamine containing a specific aromatic diamine having an ammonium sulfonate group as a main component, a phenol-based When reacted in a solvent, it is copolymerized and imidized in a single step to obtain a homogeneous aromatic polyimide solvent solution having an ammonium sulfonate group, and a semipermeable membrane such as a hollow membrane can be easily obtained. That is, the present invention has been reached.

[0008]

[Means for Solving the Problems]

In the present invention, the repeating unit is represented by the general formula (1),

[0010]

[Chemical 11]

The present invention relates to an aromatic polyimide represented by However, Y in the general formula (1) is an aromatic tetracarboxylic acid dianhydride residue, and at least 50 mol% or more thereof is the aromatic tetracarboxylic acid dianhydride residue derived from the biphenyltetracarboxylic acid dianhydride. Further, Ar in the general formula (1) is an aromatic diamine residue, and 20 to 60 mol% thereof is an aromatic diamine residue represented by the following general formula (2) and / or (3). The remaining 80 to 40 mol% is
An aromatic diamine represented by the general formula (2) and / or (3)
Is an aromatic diamine residue other than R in the general formula (2)
_At least one of _{1 to} R ₄ is —SO ₃ N (L) ₄ [L
Is a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, and is otherwise a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and at least one of R _{1 to} R _{8 in} the general formula (3) is , —SO ₃ N (L) ₄ [L is a hydrogen atom or carbon number 1
To a hydrocarbon group of 12], and the others represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.

[0012]

[Chemical 12]

[0013]

[Chemical 13]

In the present invention, an aromatic tetracarboxylic acid compound in which at least 50 mol% or more of the aromatic tetracarboxylic dianhydride is biphenyltetracarboxylic dianhydride, and 20 to 60 mol% of the aromatic diamine are generally used. Formula (4)
And / or a method for producing an aromatic polyimide in which approximately equimolar amounts of an aromatic diamine represented by (5) are copolymerized and imidized in a phenolic solvent.

[0015]

[Chemical 14]

[0016]

[Chemical 15]

However, R in the general formula (4) is₁~ R_FourSmall
At least one is -SO₃N (L) _Four[L is a hydrogen atom
Or a hydrocarbon group having 1 to 12 carbon atoms] and hydrogen otherwise.
Represents an atom or an alkyl group having 1 to 3 carbon atoms, and has the general formula
R in equation (5)₁~ R₈At least one of -SO₃
N (L)_Four[L is a hydrogen atom or carbonization having 1 to 12 carbon atoms
Hydrogen group], and the others are hydrogen atoms or C1-C3
Indicates an alkyl group.

In the present invention, the repeating unit is represented by the general formula (1),

[0019]

[Chemical 16] Relates to an aromatic polyimide semipermeable membrane.

However, Y in the general formula (1) is an aromatic tetracarboxylic dianhydride residue, at least 50 mol% or more of which is derived from the biphenyltetracarboxylic dianhydride. An anhydride residue, and also
Ar in the general formula (1) is an aromatic diamine residue, 20 to 60 mol% of which is an aromatic diamine residue represented by the following general formula (2) and / or (3), and the remaining 80 to
40 mol% is represented by the following general formula (2) and / or (3).
Is an aromatic diamine residue other than aromatic diamine, and at least one of R1 to R4 in the general formula (2) is -S
O ₃ N (L) ₄ [L is a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms], and other than that is a hydrogen atom or 1 to 12 carbon atoms.
3 is an alkyl group, and is represented by R _{1 to} R ₈ in the general formula (3).
At least one of —SO ₃ N (L) ₄ [L is a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms] and the other is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.

[0021]

[Chemical 17]

[0022]

[Chemical 18]

In the present invention, the aromatic tetracarboxylic dianhydride in which 50 mol% or more of the aromatic tetracarboxylic dianhydride is biphenyltetracarboxylic dianhydride and 20 to 60 mol% of the aromatic diamine are used. TECHNICAL FIELD The present invention relates to a method for producing an aromatic polyimide semipermeable membrane in which approximately equimolar amounts of an aromatic diamine represented by the general formula (4) and / or (5) are copolymerized and imidized in a phenolic solvent. .

[0024]

[Chemical 19]

[0025]

[Chemical 20]

However, R in the general formula (4) is₁~ R_FourSmall
At least one is -SO₃N (L) _Four[L is a hydrogen atom
Or a hydrocarbon group having 1 to 12 carbon atoms] and hydrogen otherwise.
Represents an atom or an alkyl group having 1 to 3 carbon atoms, and has the general formula
R in equation (5)₁~ R₈At least one of -SO₃
N (L)_Four[L is a hydrogen atom or carbonization having 1 to 12 carbon atoms
Hydrogen group], and the others are hydrogen atoms or C1-C3
Indicates an alkyl group.

In the present invention, in the aromatic polyimide represented by the general formula (1), at least 50 mol% or more, preferably 70 mol% or more of the aromatic tetracarboxylic dianhydride is biphenyltetracarboxylic dianhydride. Of aromatic tetracarboxylic acid dianhydride which is
About 60 mol%, preferably 30 to 50 mol% of an aromatic diamine represented by the general formula (4) and / or (5) is copolymerized with an aromatic diamine in a phenolic solvent, and an imide. It is obtained by converting. However, in the case of using benzophenonetetracarboxylic dianhydride or pyromellitic dianhydride instead of biphenyltetracarboxylic dianhydride, one-step copolymerization with a phenolic solvent, it is not possible to imidize, Copolymerization,
Even if it can be imidized, the spinnability and film-forming property are insufficient, and it is difficult to obtain a high-strength asymmetric hollow fiber membrane.

In the present invention, if the ratio of the biphenyltetracarboxylic dianhydride to the aromatic tetracarboxylic dianhydride is too low, the phenolic solvent will be
Copolymerization in one step, imidization becomes impossible, the polymer becomes insoluble in the phenol solvent, or the spinning property of the polymer solution of the phenol solvent, the film-forming property becomes worse, The content of biphenyltetracarboxylic dianhydride must be at least 50 mol% or more, preferably 70 mol% or more.

When polymerization or imidization is carried out in an amide solvent such as an N-methylpyrrolidone solvent instead of the phenol solvent, the polymerization solution gels, or the spinnability and film-forming property of the polymerization solution deteriorate. Therefore, it is difficult to form a hollow fiber membrane.

In the present invention, the biphenyltetracarboxylic dianhydride includes 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride and 2,3,3', 4'-biphenyltetracarboxylic dianhydride. Examples thereof include anhydrides and derivatives thereof, and 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride is preferably used.

Other aromatic tetracarboxylic dianhydrides that can be used in combination with the biphenyl tetracarboxylic dianhydride include aromatic tetracarboxylic dianhydrides which are conventionally known in the production of aromatic polyimides. The amount can be appropriately selected and used in an amount of mol% or less, preferably 30 mol% or less.

Other aromatic tetracarboxylic acid dianhydrides used in combination therewith are, for example, 3,3 ', 4,4'.
-Diphenyldi (trifluoromethyl) methanetetracarboxylic dianhydride, pyromellitic dianhydride, 3,
3 ', 4,4'-diphenylsulfone tetracarboxylic dianhydride, 3,3', 4,4'-benzophenone tetracarboxylic dianhydride, 3,3 ', 4,4'-diphenylmethane tetracarboxylic dianhydride Anhydrous, 3,3 ', 4,4'
-Diphenyldimethylmethanetetracarboxylic dianhydride, 3,3 ', 4,4'-diphenylethertetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride and the like can be mentioned. .

Among these, diphenyldi (trifluoromethyl) methanetetracarboxylic dianhydride is preferably selected, and in this case, the proportion of the biphenyltetracarboxylic dianhydride is 50 mol% or more, preferably 70 to 1
00 mol% and diphenyldi (trifluoromethyl)
When the proportion of methanetetracarboxylic dianhydride is less than 50 mol%, preferably 0 to 30 mol% in combination, the hollow fiber is spun from a polymerization solution which has been copolymerized and imidized in a single step in a phenol solvent to form a hollow fiber. It is preferable because the gas permeability of the membrane is improved.

In the present invention, as the aromatic diamine, 20 to 60 mol%, preferably 30 to 50 mol% of the aromatic diamine is represented by the general formula (4) and / or (5). A group diamine is used, and the aromatic diamine represented by the general formula (4) or (5) may be used alone, or the aromatic diamines represented by the general formulas (4) and (5) may be used in combination. However, if the amount of the aromatic diamine having an ammonium sulfonate group is too small, the content of the ammonium sulfonate group in the polyimide becomes small, so that the gas permeability and the selectivity of the membrane obtained by forming the hollow fiber membrane are improved. do not do. If the amount is too large, a good asymmetric structure is less likely to be formed during spinning into a hollow fiber membrane by spinning from a polymerization solution obtained by copolymerization or imidization in a phenol solvent in a single step. It is not preferable because the gas permeability is lowered.

The aromatic diamine having an ammonium sulfonate group includes, for example, a diamine having a sulfonic acid group and an alkylamine {N (L) ₃ [L is a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms]}. Obtained by harmonizing.

Specific examples of the diamine having a sulfonic acid group include 2,5-diaminobenzenesulfonic acid,
2,4-diaminobenzenesulfonic acid, 2,4-diaminobenzene-1,5-disulfonic acid, 3,3′-tolidine-5-sulfonic acid, 3,3′-tolidine-6,6′-
Examples thereof include disulfonic acid and benzidine-2,2'-disulfonic acid.

Alkylamine {N (L) ₃ [L is a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms]} is L
Is a saturated aliphatic amine consisting of a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, and specific examples thereof include ammonia, methylamine, ethylamine, propylamine, isopropylamine, butylamine, isobutylamine, sec-butylamine, Amylamine, hexylamine, dimethylamine, diethylamine, dipropylamine, diisopropylamine, dibutylamine, diisobutylamine, disec-butylamine, diamylamine, dihexylamine, trimethylamine, triethylamine, tripropylamine, triisopropylamine, tributylamine, triisobutyl Amines, birds
ec-butylamine, triamylamine, trihexylamine, cyclohexylamine, dicyclohexylamine, N, N-dimethylethylamine, N, N-dimethylisopropylamine, N, N-dimethylbutylamine,
Examples thereof include saturated aliphatic amines such as N, N-diethylmethylamine and N, N-diisopropylethylamine.

As the alkylamine {N (L) ₃ [L is a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms]}, at least one of L is an alkenyl group having 1 to 12 carbon atoms and the rest is Unsaturated aliphatic amines composed of a hydrogen atom or an alkyl group having 1 to 12 carbon atoms are mentioned, and specific examples thereof include unsaturated fatty acids such as allylamine, diallylamine, triallylamine, N-methyldiallylamine and N, N-dimethylallylamine. Group amine etc. can be mentioned.

Furthermore, alkylamine {N (L) ₃
[L is a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms]}
Is an aromatic ring-containing amine in which at least one of L is a group containing an aromatic ring and the rest is a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, and specific examples include benzylamine, dibenzylamine, Tribenzylamine,
Phenethylamine, alpha-phenylethylamine,
Examples thereof include aromatic ring-containing amines such as 1-methyl-3-phenylpropylamine, N-methyldibenzylamine and N, N-dimethylbenzylamine.

Specific examples of the aromatic diamine having an ammonium sulfonate group include ammonium 2,5-diaminobenzenesulfonate, methylammonium 2,5-diaminobenzenesulfonate, ethylammonium 2,5-diaminobenzenesulfonate, Propyl ammonium 2,5-diaminobenzene sulfonate, Isopropyl ammonium 2,5-diaminobenzene sulfonate,
2,5-Diaminobenzenesulfonic acid butylammonium salt, 2,5-diaminobenzenesulfonic acid isobutylammonium salt, 2,5-diaminobenzenesulfonic acid se
c-butylammonium, amylammonium 2,5-diaminobenzenesulfonate, hexylammonium 2,5-diaminobenzenesulfonate, dimethylammonium 2,5-diaminobenzenesulfonate, diethylammonium 2,5-diaminobenzenesulfonate, 2 ，
Dipropylammonium 5-diaminobenzenesulfonate, Diisopropylammonium 2,5-diaminobenzenesulfonate, Dibutylammonium 2,5-diaminobenzenesulfonate, Diisobutylammonium 2,5-diaminobenzenesulfonate, 2,5-Diaminobenzenesulfone Acid disec-butylammonium, 2,
Diamyl ammonium 5-diaminobenzene sulfonate, dihexyl ammonium 2,5-diaminobenzene sulfonate, trimethyl ammonium 2,5-diaminobenzene sulfonate, triethylammonium 2,5-diaminobenzene sulfonate, 2,5-diaminobenzene sulfone Acid tripropylammonium, 2,5-diaminobenzenesulfonic acid triisopropylammonium, 2,5-diaminobenzenesulfonic acid tributylammonium, 2,5-diaminobenzenesulfonic acid triisobutylammonium, 2,5-diaminobenzenesulfonic acid trisec -Butylammonium, triamylammonium 2,5-diaminobenzenesulfonate,
Trihexyl ammonium 2,5-diaminobenzene sulfonate, cyclohexylammonium 2,5-diaminobenzene sulfonate, dicyclohexylammonium 2,5-diaminobenzene sulfonate, N, N-dimethylethyl ammonium 2,5-diaminobenzene sulfonate, N, N-dimethylisopropylammonium 2,5-diaminobenzenesulfonate, N, N-dimethylbutylammonium 2,5-diaminobenzenesulfonate, N, N-diethylmethylammonium 2,5-diaminobenzenesulfonate, 2, 5-diaminobenzenesulfonic acid N, N-diisopropylethylammonium,
Allyl ammonium 2,5-diaminobenzenesulfonate, diallylammonium 2,5-diaminobenzenesulfonate, triallylammonium 2,5-diaminobenzenesulfonate, N-methyldiallylammonium 2,5-diaminobenzenesulfonate, 2, N, N-dimethylallylammonium 5-diaminobenzenesulfonate, benzylammonium 2,5-diaminobenzenesulfonate, dibenzylammonium 2,5-diaminobenzenesulfonate, tribenzylammonium 2,5-diaminobenzenesulfonate, 2 , 5-Diaminobenzenesulfonic acid phenethylammonium, 2,5-diaminobenzenesulfonic acid alpha-phenylethylammonium, 2,5-diaminobenzenesulfonic acid 1-methyl-3-phenyl B pills ammonium, 2,5-diaminobenzene sulfonic acid N- methyl dibenzyl ammonium, 2,5-diaminobenzene sulfonic acid N, N- dimethyl benzyl ammonium, and the like. Also, for example, ammonium 2,4-diaminobenzenesulfonate,
Methylammonium 2,4-diaminobenzenesulfonate, ethylammonium 2,4-diaminobenzenesulfonate, propylammonium 2,4-diaminobenzenesulfonate, isopropylammonium 2,4-diaminobenzenesulfonate, 2,4-diaminobenzene Butyl ammonium sulfonate, isobutyl ammonium 2,4-diaminobenzene sulfonate, sec-butyl ammonium 2,4-diaminobenzene sulfonate,
Amyl ammonium 2,4-diaminobenzene sulfonate, hexyl ammonium 2,4-diaminobenzene sulfonate, dimethyl ammonium 2,4-diaminobenzene sulfonate, diethyl ammonium 2,4-diaminobenzene sulfonate, 2,4-diaminobenzene Dipropyl ammonium sulfonate, 2,4-diaminobenzene diisopropyl ammonium sulfonate, 2,4-
Dibutylammonium diaminobenzenesulfonate,
2,4-diaminobenzenesulfonic acid diisobutylammonium, 2,4-diaminobenzenesulfonic acid dise
c-butylammonium, diamylammonium 2,4-diaminobenzenesulfonate, dihexylammonium 2,4-diaminobenzenesulfonate, trimethylammonium 2,4-diaminobenzenesulfonate, 2,
Triethylammonium 4-diaminobenzenesulfonate, Tripropylammonium 2,4-diaminobenzenesulfonate, Triisopropylammonium 2,4-diaminobenzenesulfonate, Tributylammonium 2,4-diaminobenzenesulfonate, 2,4-Diaminobenzene Triisobutylammonium sulfonate,
Tris-butylammonium 2,4-diaminobenzenesulfonate, triamylammonium 2,4-diaminobenzenesulfonate, trihexylammonium 2,4-diaminobenzenesulfonate, cyclohexylammonium 2,4-diaminobenzenesulfonate, 2 ，
4-Diaminobenzenesulfonic acid dicyclohexylammonium, 2,4-diaminobenzenesulfonic acid N, N
-Dimethylethylammonium, N, N-dimethylisopropylammonium 2,4-diaminobenzenesulfonate, N, N-dimethylbutylammonium 2,4-diaminobenzenesulfonate, N, N-diethyl 2,4-diaminobenzenesulfonate Methyl ammonium, 2,
N, N-diisopropylethylammonium 4-diaminobenzenesulfonate, allylammonium 2,4-diaminobenzenesulfonate, diallylammonium 2,4-diaminobenzenesulfonate, triallylammonium 2,4-diaminobenzenesulfonate, 2, N-methyldiallylammonium 4-diaminobenzenesulfonate, N, N-dimethylallylammonium 2,4-diaminobenzenesulfonate, benzylammonium 2,4-diaminobenzenesulfonate, dibenzylammonium 2,4-diaminobenzenesulfonate , Tribenzylammonium 2,4-diaminobenzenesulfonate,
Phenethylammonium 2,4-diaminobenzenesulfonate, alpha-phenylethylammonium 2,4-diaminobenzenesulfonate, 1-methyl-3-phenylpropylammonium 2,4-diaminobenzenesulfonate, 2,4-diaminobenzenesulfone Examples of the acid include N-methyldibenzylammonium acid and N, N-dimethylbenzylammonium 2,4-diaminobenzenesulfonate. Further, for example, ammonium 2,4-diaminobenzene-1,5-disulfonate, methylammonium 2,4-diaminobenzene-1,5-disulfonate, ethylammonium 2,4-diaminobenzene-1,5-disulfonate, 2 , 4-diaminobenzene-1,
Propyl ammonium 5-disulfonate, 2,4-diaminobenzene-1,5-isopropylammonium disulfonate, 2,4-diaminobenzene-1,5-butylammonium disulfonate, 2,4-diaminobenzene-1,5- Isobutylammonium disulfonate, 2,
4-diaminobenzene-1,5-disulfonic acid sec-
Butyl ammonium, 2,4-diaminobenzene-1,
Amyl ammonium 5-disulfonate, 2,4-diaminobenzene-1,5-hexyl ammonium disulfonate, 2,4-diaminobenzene-1,5-dimethyl ammonium disulfonate, 2,4-diaminobenzene-
Diethylammonium 1,5-disulfonate, 2,4-
Diaminobenzene-1,5-disulfonic acid dipropylammonium, 2,4-diaminobenzene-1,5-disulfonic acid diisopropylammonium, 2,4-diaminobenzene-1,5-disulfonic acid dibutylammonium, 2,4-diamino Benzene-1,5-disulfonic acid diisobutylammonium, 2,4-diaminobenzene-1,5-disulfonic acid disec-butylammonium, 2,4-diaminobenzene-1,5-disulfonic acid diamylammonium, 2,4 -Diaminobenzene-
Dihexyl ammonium 1,5-disulfonate, 2,4
Trimethylammonium diaminobenzene-1,5-disulfonate, triethylammonium 2,4-diaminobenzene-1,5-disulfonate, tripropylammonium 2,4-diaminobenzene-1,5-disulfonate, 2,4- Diaminobenzene-1,5-disulfonic acid triisopropylammonium, 2,4-diaminobenzene-1,5-disulfonic acid tributylammonium, 2,4-diaminobenzene-1,5-disulfonic acid triisobutylammonium, 2,4- Trisec-butylammonium diaminobenzene-1,5-disulfonate, triamylammonium 2,4-diaminobenzene-1,5-disulfonate, trihexylammonium 2,4-diaminobenzene-1,5-disulfonate,
2,4-Diaminobenzene-1,5-cyclohexylammonium disulfonate, 2,4-diaminobenzene-
1,5-disulfonic acid dicyclohexylammonium,
2,4-diaminobenzene-1,5-disulfonic acid N,
N-dimethylethylammonium, 2,4-diaminobenzene-1,5-disulfonic acid N, N-dimethylisopropylammonium, 2,4-diaminobenzene-1,
5-disulfonic acid N, N-dimethylbutylammonium, 2,4-diaminobenzene-1,5-disulfonic acid N, N-diethylmethylammonium, 2,4-diaminobenzene-1,5-disulfonic acid N, N- Diisopropylethylammonium, 2,4-diaminobenzene-
1,5-disulfonic acid allyl ammonium, 2,4-diaminobenzene-1,5-disulfonic acid diallyl ammonium, 2,4-diaminobenzene-1,5-disulfonic acid triallyl ammonium, 2,4-diaminobenzene-1 , 5-disulfonic acid N-methyldiallylammonium, 2,4-diaminobenzene-1,5-disulfonic acid N, N-dimethylallylammonium, 2,4-diaminobenzene-1,5-disulfonic acid benzylammonium, 2, 4-diaminobenzene-1,5-disulfonic acid dibenzylammonium, 2,4-diaminobenzene-1,5-disulfonic acid tribenzylammonium,
Phenethylammonium 2,4-diaminobenzene-1,5-disulfonate, 2,4-diaminobenzene-1,
5-disulfonic acid alpha-phenylethylammonium, 2,4-diaminobenzene-1,5-disulfonic acid 1-methyl-3-phenylpropylammonium, 2,
4-diaminobenzene-1,5-disulfonic acid N-methyldibenzylammonium, 2,4-diaminobenzene-1,5-disulfonic acid N, N-dimethylbenzylammonium and the like can be mentioned. Furthermore, for example, 3,3′-tolidine-5-sulfonate ammonium, 3,3′-tolidine-5-methylammonium salt, 3,3′-
Ethyl ammonium trisine-5-sulfonate, 3,
Propyl ammonium 3′-tolidine-5-sulfonate, isopropylammonium 3,3′-tolidine-5-sulfonate, butylammonium 3,3′-tolidine-5-sulfonate, 3,3′-tolidine-5-sulfone Acid isobutylammonium, 3,3'-tolidine-5-
Sec-Butyl ammonium sulfonate, 3,3′-tolidine-5-amyl ammonium sulfonate, 3,3 ′
-Tolidine-5-hexyl ammonium sulfonate,
Dimethylammonium 3,3′-tolidine-5-sulfonate, diethylammonium 3,3′-tolidine-5-sulfonate, dipropylammonium 3,3′-tolidine-5-sulfonate, 3,3′-tolidine- Diisopropylammonium 5-sulfonate, 3,3′-tolidine-5-dibutylammonium sulfonate, 3,3′-tolidine-5-diisobutylammonium sulfonate,
3,3'-Tolidine-5-sulfonate disec-butylammonium, 3,3'-Tolidine-5-sulfonate diamylammonium, 3,3'-Tolidine-5-sulfonate dihexylammonium, 3,3 ' -Toridine-5
-Trimethylammonium sulfonate, 3,3'-tolidine-5-triethylammonium sulfonate, 3,
3'-Tolidine-5-sulfonate tripropylammonium, 3,3'-Tolidine-5-sulfonate triisopropylammonium, 3,3'-Tolidine-5-sulfonate tributylammonium, 3,3'-Tolidine-5
-Triisobutylammonium sulfonate, 3,3'-
Trisine-5-sulfonate trisec-butylammonium, 3,3'-Tolidine-5-sulfonate triamylammonium, 3,3'-Tolidine-5-sulfonate trihexylammonium, 3,3'-Tolidine-5. -Cyclohexylammonium sulfonate, 3,3'-tolidine-5-dicyclohexylammonium sulfonate,
N, N-dimethylethylammonium 3,3′-tolidine-5-sulfonate, N, N-dimethylisopropylammonium 3,3′-tolidine-5-sulfonate, 3,
3'-Tolidine-5-sulfonate N, N-dimethylbutylammonium, 3,3'-Tolidine-5-sulfonate N, N-diethylmethylammonium, 3,3'-Tolidine-5-sulfonate N, N -Diisopropylethylammonium, allylammonium 3,3'-trizin-5-sulfonate, diallylammonium 3,3'-tolidine-5-sulphonate, triallylammonium 3,3'-trizin-5-sulphonate, 3, 3'-Tolidine-
N-methyldiallylammonium 5-sulfonate, 3,
3'-Tolidine-5-sulfonate N, N-dimethylallylammonium, 3,3'-Tolidine-5-benzylammonium sulfonate, 3,3'-Tolidine-5-dibenzylammonium sulfonate, 3,3 ' -Toridine-
Tribenzylammonium 5-sulfonate, 3,3'-
Phenethylammonium trisine-5-sulfonate,
Alpha-phenylethylammonium 3,3′-tolidine-5-sulfonate, 1-methyl-3-phenylpropylammonium 3,3′-tolidine-5-sulfonate, N, 3,3′-tolidine-5-sulfonate -Methyldibenzylammonium, 3,3'-tolidine-5-sulfonic acid N, N-dimethylbenzylammonium and the like can be mentioned. Further, for example, 3,3′-tolidine-6,6′-ammonium disulfonate, 3,3′-tolidine-6,
6'-disulfonic acid methyl ammonium, 3,3'-tolidine-6,6'-disulfonic acid ethyl ammonium,
Propyl ammonium 3,3′-tolidine-6,6′-disulfonate, isopropyl ammonium 3,3′-tolidine-6,6′-disulfonate, butyl ammonium 3,3′-tolidine-6,6′-disulfonate , 3,
Isobutylammonium 3'-tolidine-6,6'-disulfonate, sec-butylammonium 3,3'-tolidine-6,6'-disulfonate, amylammonium 3,3'-tolidine-6,6'-disulfonate , 3,
Hexylammonium 3'-tolidine-6,6'-disulfonate, dimethylammonium 3,3'-tolidine-6,6'-disulfonate, 3,3'-Tolidine-6,6
6'-disulfonic acid diethylammonium, 3,3'-
Trizine-6,6′-dipropylammonium disulfonate, 3,3′-tolidine-6,6′-diisopropylammonium disulfonate, 3,3′-tolidine-6,
6'-dibutylammonium disulfonate, 3,3'-
Trisine-6,6'-disulfonic acid diisobutylammonium, 3,3'-tolidine-6,6'-disulfonic acid disec-butylammonium, 3,3'-tolidine-
Diamyl ammonium 6,6'-disulfonate, 3,
3'-tolidine-6,6'-disulfonic acid dihexyl ammonium, 3,3'-tolidine-6,6'-disulfonic acid trimethyl ammonium, 3,3'-tolidine-
Triethylammonium 6,6'-disulfonate, 3,
Tripropylammonium 3'-Tolidine-6,6'-disulfonate, Triisopropylammonium 3,3'-Tolidine-6,6'-disulfonate, Tributylammonium 3,3'-Tolidine-6,6'-disulfonate , 3'-Tolidine-6,6'-triisobutylammonium disulfonate, 3,3'-Tolidine-6,
6'-disulfonic acid trisec-butylammonium,
Triamyl ammonium 3,3′-tolidine-6,6′-disulfonate, trihexyl ammonium 3,3′-tolidine-6,6′-disulfonate, 3,3′-tolidine-6,6′-disulfonic acid Cyclohexylammonium, 3,3′-tolidine-6,6′-dicyclohexylammonium disulfonate, 3,3′-tolidine-6,
6'-disulfonic acid N, N-dimethylethylammonium, 3,3'-tolidine-6,6'-disulfonic acid N,
N-dimethylisopropylammonium, N, N-dimethylbutylammonium 3,3′-tolidine-6,6′-disulfonate, N, N-diethylmethylammonium 3,3′-tolidine-6,6′-disulfonate, Three
3'-tolidine-6,6'-disulfonic acid N, N-diisopropylethylammonium, 3,3'-tolidine-
Allyl ammonium 6,6'-disulfonate, 3,3 '
-Trizine-6,6'-diallylammonium disulfonate, 3,3'-trizine-6,6'-triallylammonium disulfonate, 3,3'-tolidine-6,6 '
-N-methyldiallylammonium disulfonate, 3,
3'-tolidine-6,6'-disulfonic acid N, N-dimethylallylammonium, 3,3'-tolidine-6,
6'-benzylammonium disulfonate, 3,3'-
Trizine-6,6′-dibenzylammonium dibenzylammonium, 3,3′-Tolidine-6,6′-dibenzylammonium tribenzylammonium, 3,3′-Tolidine-6,
Phenethylammonium 6'-disulfonate, 3,3 '
-Tolidine-6,6'-alpha-phenylethylammonium disulfonate, 3,3'-Tolidine-6,6 '
-1-methyl-3-phenylpropylammonium disulfonate, N-methyldibenzylammonium 3,3'-trizine-6,6'-disulfonate, 3,3'-tolidine-6,6'-disulfonic acid N, N-dimethylbenzyl ammonium etc. are mentioned. Furthermore, for example, ammonium benzidine-2,2'-disulfonate, methylammonium benzidine-2,2'-disulfonate, ethylammonium benzidine-2,2'-disulfonate, propylammonium benzidine-2,2'-disulfonate, benzidine Isopropylammonium-2,2'-disulfonate, benzidine-2,2'-butylammonium disulfonate, benzidine-2,2'-isobutylammonium disulfonate, sec-butylammonium benzidine-2,2'-disulfonate, benzidine −
2,2′-amyl ammonium disulfonate, benzidine-2,2′-hexyl ammonium disulfonate, benzidine-2,2′-dimethyl ammonium sulfonate, benzidine-2,2′-diethyl ammonium diethylsulfonate, benzidine-2, 2'-disulfonic acid dipropylammonium, benzidine-2,2'-disulfonic acid diisopropylammonium, benzidine-2,2 '
-Dibutylammonium disulfonate, benzidine-
2,2'-disulfonic acid diisobutylammonium, benzidine-2,2'-disulfonic acid disec-butylammonium, benzidine-2,2'-disulfonic acid diamylammonium, benzidine-2,2'-disulfonic acid dihexylammonium, Benzidine-2,2′-trimethylammonium sulfonate, benzidine-2,
2'-disulfonic acid triethylammonium, benzidine-2,2'-disulfonic acid tripropylammonium, benzidine-2,2'-disulfonic acid triisopropylammonium, benzidine-2,2'-disulfonic acid tributylammonium, benzidine-2, 2'-disulfonic acid triisobutylammonium, benzidine-
Trisec-butylammonium 2,2′-disulfonate, Triamylammonium benzidine-2,2′-disulfonate, Trihexylammonium benzidine-2,2′-disulfonate, Cyclohexylammonium benzidine-2,2′-disulfonate , Benzidine-2,
Dicyclohexylammonium 2′-disulfonate, N, N-dimethylethylammonium benzidine-2,2′-disulfonate, N, N-dimethylisopropylammonium benzidine-2,2′-disulfonate, benzidine-2,2′-disulfone Acid N, N-dimethylbutylammonium, benzidine-2,2'-disulfonic acid N, N-diethylmethylammonium, benzidine-
N, N-diisopropylethylammonium 2,2′-disulfonate, allyl ammonium benzidine-2,2′-disulfonate, diallylammonium benzidine-2,2′-disulfonate, triallyl benzidine-2,2′-disulfonate Ammonium, benzidine-2,
2'-disulfonic acid N-methyldiallylammonium,
Benzidine-2,2'-disulfonic acid N, N-dimethylallylammonium, benzidine-2,2'-disulfonic acid benzylammonium, benzidine-2,2'-disulfonic acid dibenzylammonium, benzidine-2,
2'-disulfonic acid tribenzylammonium, benzidine-2,2'-disulfonic acid phenethylammonium, benzidine-2,2'-disulfonic acid alpha-phenylethylammonium, benzidine-2,2'-disulfonic acid 1-methyl-3 -Phenylpropylammonium, benzidine-2,2'-disulfonic acid N-methyldibenzylammonium, benzidine-2,2'-disulfonic acid N, N-dimethylbenzylammonium and the like can be mentioned.

As the other aromatic diamine used in combination with the aromatic diamine having an ammonium sulfonate group, conventionally known aromatic diamines can be mentioned. Specific examples thereof include diaminodiphenyl ethers such as 4,4′-diaminodiphenyl ether, 3,4′-diaminodiphenyl ether, and 3,3′-diaminodiphenyl ether, 4,4′-diaminodiphenylmethane, and 3,4′-diaminodiphenylmethane. , 3,
Diaminodiphenylmethanes such as 3′-diaminodiphenylmethane, 2,2′-bis (3-aminophenyl) propane, 2,2′-bis (4-aminophenyl) propane, 2,2′-bis (4-aminophenyl) ) Bis (aminophenyl) propanes such as hexafluoropropane,
4,4'-diaminodiphenyl sulfone, 3,4'-diaminodiphenyl sulfone and other diaminodiphenyl sulfones, 4,4'-diaminobenzophenone, 3,4 '
-Diaminobenzophenones such as diaminobenzophenone, 2,7-diamino-3,6-dimethyldibenzothiophenesulphone, 2,8-diamino-3,7-dimethyldibenzothiophenesulphone, 3,7-diamino-
Diaminodimethyldibenzothiophenesulphones such as 2,8-dimethyldibenzothiophenesulphone, 1,
4-bis (3-aminophenoxy) benzene, 1,4-
Bis (aminophenoxy) benzenes such as bis (4-aminophenoxy) benzene, bis (aminophenyl) such as 1,4-bis (3-aminophenyl) benzene and 1,4-bis (4-aminophenyl) benzene Benzenes,
2,2-bis [4- (3-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-
Aminophenoxy) phenyl] hexafluoropropane and other bis [(aminophenoxy) phenyl] propanes, 2,2-bis [4- (3-aminophenoxy) phenyl] sulfone, 2,2-bis [4- (4- Examples thereof include bis [(aminophenoxy) phenyl] sulfones such as aminophenoxy) phenyl] sulfone and phenylenediamines.

These other aromatic diamines to be used in combination can be used alone or in combination with the aromatic diamine having an ammonium sulfonate group. In that case,
The amount of the aromatic diamine having an ammonium sulfonate group used is 20 to 60 mol%, preferably 30 to 50 mol%.
As the other aromatic diamine to be used in combination, diaminobenzothiophenesulfone, particularly 3,7-diamino-2,8-dimethyldibenzothiophenesulfone, is used together to improve the gas permeability and the selectivity of the aromatic polyimide. It is preferable because a semipermeable membrane can be obtained, and the amount thereof is 40 to 80 mol%, particularly preferably 50 to 70.
Mol%.

As the phenolic solvent of the present invention, a solvent having a melting point of about 100 ° C. or lower, preferably 80 ° C. or lower, and a boiling point at atmospheric pressure of 300 ° C. or lower, preferably 280 ° C. or lower is a solvent in the polymerization solution. It is preferable because there is no problem in handling the polymerization solution such as freezing. Specific examples of the phenolic solvent include monovalent phenols such as phenol, o-, m- or p-cresol, 3,5-xylenol, carvacrol and thymol, catechols, or 3-chlorophenol, 4-chlorophenol. Chlorophenol, 3-
Bromophenol, 4-bromophenol, 2,4-dibromophenol, 2-chloro-4-hydroxytoluene, 2-chloro-5-hydroxytoluene, 3-chloro-6-hydroxytoluene, 4-chloro-2-hydroxytoluene. , 2-bromo-4-hydroxytoluene, 2
-Bromo-5-hydroxytoluene, 3-bromo-6-
Examples thereof include halogenated phenols obtained by substituting a hydrogen atom of a benzene ring of a monovalent phenol such as hydroxytoluene and 4-bromo-2-hydroxytoluene with a halogen atom. Among them, halogenated phenol is preferable, and particularly 4- Chlorophenol is preferred. These phenolic solvents may be used alone or as a mixed solvent of plural kinds.

In the present invention, for copolymerization and imidization in a phenolic solvent, usually, an aromatic tetracarboxylic dianhydride and an aromatic diamine are dissolved in a phenolic solvent in an approximately equimolar amount to 100 to 100%. 250 ° C, preferably 130
It is possible to obtain a practically sufficient polymerization rate and to suppress the evaporation and desorption of the solvent from the polymerization system, by carrying out the reaction by heating to a reaction temperature of up to 200 ° C. and removing the produced water. Therefore, it is preferable. The reaction may be carried out batchwise or continuously.

A polycondensation reaction and an imidization reaction proceed at the above reaction temperature, and a solution of an aromatic polyimide containing an aromatic diamine having an ammonium sulfonate group dissolved in a phenolic solvent as a copolymerization component is prepared in a single step. can get. The reaction time is about 10 to 60 hours. At that time, the amount of the aromatic tetracarboxylic dianhydride and the aromatic diamine used with respect to the phenolic solvent is 5 to 50% by weight of the aromatic polyimide in the solvent (concentration). When used in the production of a semipermeable membrane such as a membrane, the concentration is preferably 5 to 30% by weight, more preferably 5 to 20% by weight, and the rotational viscosity of the polymerization liquid (measured at 100 ° C.) is 10%. -10,000 poise, especially 100-6000
Poise is preferred. If the rotational viscosity is too high or too low, spinnability and film-forming property will suffer, which is not preferable.

In the present invention, the semipermeable membrane is formed from an aromatic polyimide solution having an ammonium sulfonate group obtained by copolymerization or imidization by a film forming method such as a dry method, a wet method or a dry / wet method. can do. In particular, according to a dry-wet method in which a solution of an aromatic polyimide is cast or discharged from a molding machine into the air or extruded, then it is introduced into a coagulating liquid to coagulate, and the adhering coagulating liquid is washed and dried. It is preferable because a semipermeable membrane having excellent properties and selectivity can be obtained.

The coagulating liquid used in the wet method or the dry-wet method for obtaining the semipermeable membrane is, for example, water or an alcohol solvent such as methanol, ethanol, propanol or isopropanol, acetone, methyl ethyl ketone, diethyl ketone or ethyl propyl. A polar solvent that does not dissolve an aromatic polyimide, such as a ketone solvent such as a ketone, a mixed solvent of these water, an alcohol solvent, a ketone solvent, and the like, and that is compatible with the solvent of the aromatic polyimide solution is used. Among them, a mixed solvent of water, particularly a mixed solvent of water and an alcoholic solvent, for example, a mixed solvent of water and ethanol, has a defect-free gas permeability, an asymmetric semipermeable membrane excellent in selectivity. It is preferable because it can be formed.

The coagulated aromatic polyimide semipermeable membrane is washed with an alcohol solvent such as methanol, ethanol, propanol or isopropanol, and then an inert solvent such as isopentane, n-hexane, isooctane or n-heptane. Washing with an aliphatic hydrocarbon solvent such as, drying, and further heat treatment. The heat treatment temperature is preferably lower than the softening point or the second-order transition point of the semipermeable membrane having an ammonium sulfonate group, because it does not destroy the asymmetric structure of the asymmetric semipermeable membrane. It is preferable that the heat treatment temperature is appropriately selected from 90 to 400 ° C., particularly 200 to 350 ° C., because the hollow fiber membrane has a good balance of permeability and separability.

In the present invention, the shape of the semipermeable membrane having an ammonium sulfonate group may be any shape such as a film, a flat membrane on a sheet and a hollow fiber hollow fiber membrane, but as a separation membrane. Hollow fiber membranes that can have a large effective membrane area are preferable.

In the present invention, an aromatic polyimide solution having an ammonium sulfonate group obtained by copolymerization and imidization in a phenolic solvent is used as a dope solution and extruded into the air from a hollow fiber spinning nozzle to produce a hollow fiber. After forming the filamentous shaped product, the shaped product is introduced into a coagulating liquid to be coagulated and washed with an alcohol solvent and an aliphatic hydrocarbon solvent to obtain an aromatic polyimide hollow fiber membrane.

At this time, the rotational viscosity of the dope solution is 10 to 10
000 poise, 100-6000 poise is preferable, and the discharge temperature of the spinning nozzle is 30-150 ° C., preferably 4
It is 0 to 100 ° C. Further, as the coagulating liquid for holding the molded product, methanol, ethanol, propanol, an alcohol solvent such as isopropanol or a mixed solvent of water and the alcohol solvent described above, preferably methanol, ethanol, or these and water. The mixed solvent is preferable because it can form a hollow fiber membrane having a good asymmetric structure. The temperature of the coagulation liquid is -10 to + 60 ° C, preferably -5 to + 40 ° C. In addition, as the cleaning liquid, the above-mentioned alcohol solvents, among them, methanol and ethanol are preferably mentioned, and aliphatic hydrocarbon solvents such as isopentane, n-hexane, isooctane and n-heptane, preferably n-hexane and isooctane. Is mentioned.

Further, the evaporation temperature of the washing solvent is 50 to 1
Drying at a temperature of 50 ° C., preferably 80 to 150 ° C. is suitable because the evaporation time of the solvent can be shortened and the amount of residual solvent in the hollow fiber membrane can be reduced. Furthermore,
After drying, heat treatment of the hollow fiber membrane is preferable in that a hollow fiber membrane having an asymmetric ammonium sulfonate group suitable as a separation membrane can be obtained. At this time, the heat treatment temperature is preferably lower than the softening point or second-order transition point of the hollow fiber membrane having an ammonium sulfonate group, because it does not destroy the asymmetric structure of the asymmetric semipermeable membrane. And the temperature appropriately selected from the temperature of 90 to 400 ° C., particularly 200 to 350 ° C., is the permeability of the hollow fiber membrane,
It is preferable because the balance of separability becomes good.

The asymmetric hollow fiber membrane thus obtained has a high strength and is extremely excellent in gas selectivity and permeability. For example, separation of water in air, separation of helium-nitrogen, and hydrogen. It can be suitably used as a separation membrane for separation or separation of carbon dioxide gas. In particular, since the water vapor permeation rate is high and the permeation rate ratio with other gases is also high, it is suitable as a water vapor separation membrane from a mixed gas, for example, a gas separation membrane in the drying of air, the separation of water from organic vapor, and the like. is there.

[0054]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will now be described with reference to Examples and Comparative Examples.

[0055]

【Example】

[Permeability of hollow fiber membrane] Examples 1 to 13 and Comparative Example 1
In each of Examples 2 to 2, the permeation performance of the hollow fiber membrane was evaluated as follows. A hollow fiber membrane, a stainless steel pipe, and an epoxy resin adhesive were used to prepare a bundle of hollow fiber membranes with open ends at both ends for evaluation of permeation performance, and the bundle was housed in a stainless steel container to form a module. The effective membrane area of the hollow fiber membrane bundle was about 3 cm ² . N ₂ gas accompanied by about 1500 ppm of water was introduced into the module, and the introduced gas was brought into contact with the outer surface of the hollow fiber membrane at a pressure difference between the outer side and the inner side of the hollow fiber membrane of 5 kg / cm ² . It was permeated to the inside of the hollow fiber membrane, and the inside of the hollow fiber was swept with dry argon gas. The water vapor and nitrogen permeation rates (P ') were calculated from the measured values of the permeated gas by gas chromatography analysis, the measured values of the feed gas, the non-permeated gas and the permeated gas by the dew point meter, and the permeated gas flow rate. . The measurement temperature was 50 ° C. The unit of the transmission rate (P ′) is cm ³ (STP) / cm ² · sec · cmHg.

Example 1 [Preparation of aromatic polyimide solution] 3,3 ', 4,4',
Biphenyltetracarboxylic dianhydride (BPDA) 9
261 g of 4-chlorophenol, 9 mmol, 30 mmol of triethylammonium 2,4′-diaminobenzenesulfonate (mBS-NEt ₃ ) and 70 mmol of 3,7′-diamino-2,8-dimethyl-dibenzothiophenesulphone. At the same time, the mixture was placed in a separable flask equipped with a stirrer and a nitrogen gas introduction tube, and copolymerized and imidized at a temperature of 180 ° C. for about 40 hours under stirring to dissolve in 4-chlorophenol. A solution of an aromatic polyimide having an ammonium sulfonate group and a polyimide concentration of 17% by weight was prepared. The rotational viscosity of this aromatic polyimide solution at 100 ° C. is 10
It was 80 poise.

[Production of Hollow Fiber Membrane] The prepared aromatic polyimide solution was filtered through a 400-mesh stainless steel wire net to prepare a spinning dope. The spinning dope is prepared by using a hollow fiber spinning nozzle (outer diameter of the circular opening: 1000).
μm, slit opening width of circular opening: 200 μm, outer diameter of core opening: 400 μm) and charged into a spinning fiber from a hollow fiber spinning nozzle into a hollow fiber shape,
Then, after passing the hollow fiber shaped product through a dry nitrogen gas atmosphere, it is immersed in a primary coagulation liquid of a temperature of 0 ° C. consisting of an aqueous ethanol solution having a concentration of 70% by weight, and further in a secondary coagulation device equipped with a pair of guide rolls. By reciprocating between the guide rolls in the secondary coagulation liquid having a temperature of 0 ° C., the hollow fiber-shaped molded product is completely coagulated to form a hollow wet film, and the take-up roll takes up at a speed of 15 m / min. I took it in and spun it.

The aromatic polyimide hollow fiber wet membrane was wound on a bobbin, thoroughly washed with ethanol, replaced with isooctane, and heated to 100 ° C. to evaporate and dry isooctane. , 27
A heat treatment was performed at 0 ° C. for 30 minutes to produce an asymmetric aromatic polyimide hollow fiber membrane having an ammonium sulfonate group. Table 2 shows the outer diameter and thickness of the obtained asymmetric aromatic polyimide hollow fiber membrane having ammonium sulfonate group.
Further, Table 3 shows the results of evaluation of the permeation performance.

Examples 2 to 13 An aromatic polyimide solution was prepared by using the compounds shown in Table 1 as the aromatic tetracarboxylic dianhydride component and the aromatic diamine component, and the concentration and fragrance of the ethanol aqueous solution of the primary coagulation liquid were measured. An asymmetric aromatic polyimide hollow fiber membrane having an ammonium sulfonate group was produced in the same manner as in Example 1 except that the heat treatment temperature of the group wet membrane was set to the conditions shown in Table 2. The polyimide concentrations of the aromatic polyimide solutions of Examples 2 to 13 and the rotational viscosity at 100 ° C. are shown in Table 1, and the obtained asymmetric aromatic polyimide hollow fiber membranes are
The outer diameter and the film thickness are shown in Table 2, and the permeation performance evaluation results are shown in Table 3.

Comparative Examples 1-2 An aromatic polyimide solution was prepared by using the compounds shown in Table 1 as the aromatic tetracarboxylic dianhydride component and the aromatic diamine component, and the concentration and fragrance of the aqueous ethanol solution as the primary coagulating liquid were used. An asymmetric aromatic polyimide hollow fiber membrane having an ammonium sulfonate group was produced in the same manner as in Example 1 except that the heat treatment temperature of the group wet membrane was set to the conditions shown in Table 2. The polyimide concentrations of the aromatic polyimide solutions of Comparative Examples 1 and 2 and the rotational viscosity at 100 ° C. are shown in Table 1, and the obtained asymmetric aromatic polyimide hollow fiber membranes are
The outer diameter and the film thickness are shown in Table 2, and the permeation performance evaluation results are shown in Table 3.

The abbreviations in Table 1 mean the following compounds, respectively. sBPDA: 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride 6FDA: 3,3 ′, 4,4′-diphenyldi (trifluoromethyl) methanetetracarboxylic dianhydride, TSN: 3,7 '-Diamino-2,8-dimethyl-dibenzothiophensulphone TCB: 2,2', 5,5'-tetrachloro-4,4'-diaminobiphenyl DADE: 4,4'-diaminodiphenyl ether mPD: metaphenylenediamine mBS-Et ₃ N: 2,4'- diaminobenzene sulfonic acid triethyl Le ammonium _{mBS-iPr 2 Et 3 N:} 2,4'- diaminobenzene sulfonic acid N, N-diisopropylethylamine ammonium mBS-nBu ₃ N: 2, 4'-aminobenzenesulfonic acid tri n- butylammonium mBS-Ally ₂ HN 2,4'-aminobenzenesulfonic acid diallyl ammonium mBS-Ally ₃ N: 2,4'- diaminobenzene sulfonic acid triaryl Le ammonium mBS-BzMe ₂ N: 2,4'- diaminobenzene sulfonic acid N, N-dimethylbenzylamine Ammonium mBS-Bz ₂ HN: 2,4′-diaminobenzenesulfonic acid dibenzylammonium mBDS-Et ₃ N: 2,4′-diamino-1,5-benzenedisulfonic acid triethylammonium TDA-Et ₃ N: 3 , 3'-Tolidine-6,6'-triethylammonium disulfonate

[0062]

[Table 1]

[0063]

[Table 2]

[0064]

[Table 3]

[0065]

Industrial Applicability According to the present invention, it is possible to provide an aromatic polyimide semipermeable membrane having an ammonium sulfonate group, which is excellent in spinnability and film-forming property and has high gas permeability and high selectivity. Further, according to the present invention, polymerization and imidization can be performed in one step, and a solution of an aromatic polyimide having an ammonium sulfonate group, which is excellent in spinnability and film-forming property, can be easily obtained. Further, an asymmetric hollow fiber membrane having a high-strength ammonium sulfonate group having excellent gas permeability and selectivity can be easily produced.

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) C08G 73/00-73/26 C08L 79/00-79/08

Claims (13)

(57) [Claims] 1. The repeating unit is represented by the general formula (1): An aromatic polyimide represented by. However, Y in the general formula (1) is an aromatic tetracarboxylic acid dianhydride residue, and at least 50 mol% or more thereof is the aromatic tetracarboxylic acid dianhydride residue derived from the biphenyltetracarboxylic acid dianhydride. In the general formula (1), Ar represents an aromatic diamine residue, 20 to 60 mol% of which is represented by the following general formula (2).
And / or an aromatic diamine residue shown in (3),
The remaining 80 to 40 mol% is the following general formula (2) and / or
Is an aromatic diamine residue other than the aromatic diamine shown in (3)
At least one of R _{1 to} R _{4 in} the formula (2) is —SO ₃ N (L) ₄ [L is a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms], and Represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and at least one of R _{1 to} R _{8 in} the formula (3) is —SO ₃ N (L) ₄
[L is a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms]
And the others represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. [Chemical 2] [Chemical 3] 2. An aromatic tetracarboxylic dianhydride residue derived from biphenyltetracarboxylic dianhydride of the aromatic tetracarboxylic dianhydride residue represented by Y in the general formula (1) is The aromatic diamine residue represented by Ar is 70 to 100 mol%, and the aromatic diamine residue derived from the general formula (2) and / or (3) is 30 to 50 mol%. Aromatic polyimide. 3. An aromatic tetracarboxylic acid dianhydride residue derived from biphenyltetracarboxylic acid dianhydride, which is an aromatic tetracarboxylic acid dianhydride residue represented by Y in the general formula (1), is Aromatic tetracarboxylic acid dianhydride residues derived from 70 to 100 mol% and diphenyldi (trifluoromethyl) methanetetracarboxylic acid dianhydride are 0
The aromatic polyimide according to claim 2, which is ˜30 mol%. 4. An aromatic tetracarboxylic acid compound in which at least 50 mol% or more of the aromatic tetracarboxylic dianhydride is biphenyltetracarboxylic dianhydride, and 20 to 60 mol% of the aromatic diamine is represented by the general formula ( 4) and / or (5) the aromatic diamine, which is an aromatic diamine, in approximately equimolar amounts to monovalent phenols, catechols and
The method for producing an aromatic polyimide according to claim 1, wherein the aromatic polyimide is copolymerized and imidized in any solvent selected from halogenated phenols . [Chemical 4] [Chemical 5] However, at least one of R _{1 to} R _{4 in} the general formula (4) is —SO ₃ N (L) ₄ [L is a hydrogen atom or a carbon number 1
To 12 hydrocarbon groups], and the others represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and R in the general formula (5)
_At least one of _{1 to} R ₈ is —SO ₃ N (L) ₄ [L
Represents a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms], and the others represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. 5. Aromatic tetracarboxylic acid dianhydride 70-
100 mol% is biphenyltetracarboxylic dianhydride, and 30 to 50 mol% of the aromatic diamine is the general formula (4).
And / or the aromatic diamine represented by (5), The method for producing an aromatic polyimide according to claim 4. 6. An aromatic tetracarboxylic dianhydride 70-
The method for producing an aromatic polyimide according to claim 5, wherein 100 mol% is biphenyltetracarboxylic dianhydride and 0 to 30 mol% is diphenyldi (trifluoromethyl) methanetetracarboxylic dianhydride. 7. The repeating unit has the general formula (1): An aromatic polyimide semipermeable membrane represented by. However, Y in the general formula (1) is an aromatic tetracarboxylic acid dianhydride residue, and at least 50 mol% or more thereof is the aromatic tetracarboxylic acid dianhydride residue derived from the biphenyltetracarboxylic acid dianhydride. Further, Ar in the general formula (1) is an aromatic diamine residue, and 20 to 60 mol% thereof is an aromatic diamine residue represented by the following general formula (2) and / or (3). And the remaining 80 to 40 mol% is represented by the following general formula (2).
And / or an aromatic other than the aromatic diamine shown in (3)
It is a diamine residue, and at least one of R _{1 to} R _{4 in} the general formula (2) is —SO ₃ N (L) ₄ [L is a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms]. , And the others represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and at least one of R _{1 to} R _{8 in} the formula (3) is —SO ₃
N (L) ₄ [L is a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms] and the other is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. [Chemical 7] [Chemical 8] 8. An aromatic tetracarboxylic acid dianhydride residue derived from biphenyltetracarboxylic acid dianhydride of the aromatic tetracarboxylic acid dianhydride residue represented by Y in the formula (1) is The aromatic diamine residue represented by Ar is 70 to 100 mol%, and the aromatic diamine residue derived from the general formula (2) and / or (3) is 30 to 50 mol%. Aromatic polyimide semi-permeable membrane. 9. An aromatic tetracarboxylic acid dianhydride residue derived from biphenyltetracarboxylic acid dianhydride of the aromatic tetracarboxylic acid dianhydride residue represented by Y in the general formula (1), Aromatic tetracarboxylic dianhydride residues derived from diphenyldi (trifluoromethyl) methanetetracarboxylic dianhydride at 0-100 mol% are 0
The aromatic polyimide semipermeable membrane according to claim 8, which is -30 mol%. 50. Aromatic tetracarboxylic dianhydride 50
20 to 60 mol% of the aromatic diamine, and 20 to 60 mol% of the aromatic diamine are represented by the general formula (4) and / or (5).
In an aromatic diamine represented monovalent phenols approximately equimolar with the aromatic diamine, catechols and halogen
The method for producing an aromatic polyimide semipermeable membrane according to claim 7, wherein the aromatic polyimide semipermeable membrane is copolymerized and imidized in any solvent selected from the group consisting of carboxylic acid phenols . [Chemical 9] [Chemical 10] However, at least one of R _{1 to} R _{4 in} the general formula (4) is —SO ₃ N (L) ₄ [L is a hydrogen atom or a carbon number 1
To 12 hydrocarbon groups], and the others represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and R in the general formula (5)
_At least one of _{1 to} R ₈ is —SO ₃ N (L) ₄ [L
Represents a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms], and the others represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. 11. Aromatic tetracarboxylic acid dianhydride 70
To 100 mol% is biphenyltetracarboxylic dianhydride, and 30 to 50 mol% of the aromatic diamine is represented by the general formula (4).
And / or the aromatic diamine represented by (5), The method for producing an aromatic polyimide semipermeable membrane according to claim 10. 12. Aromatic tetracarboxylic dianhydride 70
12. 100 mol% is biphenyltetracarboxylic dianhydride, and 0-30 mol% is diphenyldi (trifluoromethyl) methanetetracarboxylic dianhydride.
The method for producing an aromatic polyimide semipermeable membrane according to 1. 13. The method for producing an aromatic polyimide semipermeable membrane according to claim 12, wherein the aromatic polyimide semipermeable membrane is a hollow fiber membrane.