Method for producing aromatic polysulfone

Abstract

To provide a method for producing aromatic polysulfone capable of producing aromatic polysulfone to which a polar group is introduced.SOLUTION: A method for producing aromatic polysulfone includes a step of reacting an aromatic polysulfone precursor with a compound represented by (A), wherein the aromatic polysulfone precursor has a repeating unit including a structure represented by formula (S-1) in a main chain, and has a halogen atom at a main chain terminal, and the step is performed in the presence of alkali metal salt and a phase-transfer catalyst, in an aprotic organic solvent. Formula (S-1): -ph1-SO2-ph2-O-. In the formula (S-1), ph1 and ph2 are phenylene groups which may have a substituent. Formula (A): (Ra)x-Ar-OM. In the formula (A), Ar represents an aromatic hydrocarbon group which may have a substituent, and Ra represents one or more polar groups selected from the group consisting of an acidic group having pKa equal to or less than pKa of a carboxy group and a salt of the acidic group, and functional groups containing nitrogen atoms, x is an integer of 1 or more, and M is a hydrogen atom or monovalent cation.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a method for producing an aromatic polysulfone.

Background Art

[0002] Aromatic polysulfones have properties such as excellent heat resistance, mechanical properties, electrical properties, and hydrolysis resistance. Therefore, aromatic polysulfones are used in various applications such as the electrical and electronic fields, mechanical fields, automotive fields, aircraft fields, and medical and food industrial fields.

[0003] Also, depending on the application, a hydrophilized aromatic polysulfone is required. Specific examples of such a hydrophilized aromatic polysulfone include aromatic polysulfones having a polar group.

[0004] Patent Document 1 proposes an internal pressure type hollow fiber NF membrane using sulfonated polyethersulfone, which is a hydrophilized aromatic polysulfone. This Patent Document 1 discloses an internal pressure type hollow fiber NF membrane composed of a mixture containing sulfonated polyethersulfone and polyethersulfone.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] When an aromatic polysulfone is used as a material for forming a separation membrane, a high water permeability is required for the separation membrane formed from the aromatic polysulfone. High water permeability means that the amount of water permeating through the membrane per unit time is large under a given pressure. In Patent Document 1 mentioned above, a hollow fiber type NF membrane with high water permeability is realized by using a sulfonated polyethersulfone into which a sulfonic acid group is introduced as a polar group.

[0007] The sulfonated polyethersulfone used in Patent Document 1 mentioned above is produced by sulfonating polyethersulfone using sulfuric acid or chlorosulfonic acid. However, the reaction using such strong acids is limited by the available production equipment. Also, in the above reaction, a large amount of salt is generated in the neutralization reaction during post-treatment. Therefore, a simpler method has been demanded as a method for producing a polysulfone into which a polar group such as a sulfone group is introduced.

[0008] The present invention has been made in view of such circumstances, and an object thereof is to provide a method for producing an aromatic polysulfone that enables easy production of an aromatic polysulfone into which a polar group is introduced.

Means for Solving the Problems

[0009] In order to solve the above problems, one aspect of the present invention includes the following aspects.

[0010] [1] A step of reacting an aromatic polysulfone precursor with at least one compound represented by the following formula (A), The aromatic polysulfone precursor has a repeating unit represented by the following general formula (S-1) in the main chain and a halogen atom at the main chain terminal, The step is a method for producing an aromatic polysulfone carried out in an aprotic organic solvent in the presence of at least one alkali metal salt and at least one phase transfer catalyst. -ph 1 -SO2-ph 2 -O- …(S-1) [In formula (S-1), ph 1and ph 2 is each independently a phenylene group which may have a substituent. (Ra) x -Ar-OM …(A) [In formula (A), Ar is an aromatic hydrocarbon group which may have a substituent. Ra is one or more polar groups selected from an acidic group having a pKa equal to or lower than the pKa of a carboxy group, a salt of the acidic group, and a functional group containing a nitrogen atom. x is an integer of 1 or more. M is a hydrogen atom or a monovalent cation

[0011] [2] The amount of the phase transfer catalyst is 10 mol% or more and 1000 mol% or less with respect to the alkali metal salt, in the method for producing an aromatic polysulfone according to [1].

[0012] [3] The reaction temperature of the step is 130°C or more and less than 200°C, in the method for producing an aromatic polysulfone according to [1] or [2].

[0013] [4] The phase transfer catalyst is 18-crown-6-ether, in the method for producing an aromatic polysulfone according to any one of [1] to [3].

[0014] [5] The alkali metal salt is a potassium salt, in the method for producing an aromatic polysulfone according to any one of [1] to [4].

[0015] [6] Ra is a sulfonic acid group, a salt of a sulfonic acid group, or an amino group, in the method for producing an aromatic polysulfone according to any one of [1] to [5].

[0016] [7] Ra is a sulfonic acid group or a salt of a sulfonic acid group, in the method for producing an aromatic polysulfone according to any one of [1] to [6]. [Advantages of the Invention]

[0017] According to the present invention, it is possible to provide a method for producing an aromatic polysulfone that enables the easy production of an aromatic polysulfone into which a polar group is introduced.

Mode for Carrying Out the Invention

[0018] 《Method for Producing Aromatic Polysulfone》 The method for producing an aromatic polysulfone according to the present embodiment has a repeating unit represented by the following general formula (S-1) in the main chain and an aromatic polysulfone precursor having a halogen atom at the main chain terminal, and at least one compound represented by the following formula (A). And a step of reacting. This step of reacting is carried out in an aprotic organic solvent in the presence of at least one alkali metal salt and at least one phase transfer catalyst. -ph 1 -SO2-ph 2 -O- …(S-1) [In formula (S-1), ph 1 and ph 2 are each independently a phenylene group which may have a substituent.] (Ra) x -Ar-OM …(A) [In formula (A), Ar is an aromatic hydrocarbon group which may have a substituent. Ra is one or more polar groups selected from an acidic group having a pKa equal to or lower than the pKa of a carboxy group, a salt of the acidic group, and a functional group containing a nitrogen atom. x is an integer of 1 or more. M is a hydrogen atom or a monovalent cation]

[0019] Hereinafter, the structure of the resulting aromatic polysulfone will be described, and then the method for producing the aromatic polysulfone of the present embodiment will be described in detail.

[0020] [Aromatic Polysulfone] The aromatic polysulfone has at least one polar group selected from acidic groups having a pKa below that of the carboxy group, salts of said acidic groups, and functional groups containing a nitrogen atom at the main chain terminals. In the following description, an aromatic hydrocarbon group having at least one polar group selected from acidic groups having a pKa below that of the carboxy group, salts of said acidic groups, and functional groups containing a nitrogen atom may be referred to as "FG".

[0021] In the following description, the "acidic group having a pKa below that of the carboxy group", the "salt of the acidic group having a pKa below that of the carboxy group", and the "functional group containing a nitrogen atom" may be collectively referred to as "Ra" used in the above formula (A).

[0022] (Structure 1 of the main chain) The aromatic polysulfone has a repeating unit represented by the above formula (S-1) in the main chain. ph in formula (S-1) 1 and ph 2 The phenylene group in may be a p-phenylene group, an m-phenylene group, or an o-phenylene group, but is preferably a p-phenylene group.

[0023] Examples of the substituent that the phenylene group may have include an alkyl group and an aryl group. The number of substituents that the phenylene group has is independently 0 to 4, preferably 0 to 2, more preferably 0 to 1, and even more preferably 0. When the phenylene group has a plurality of substituents, the plurality of substituents may be the same or different.

[0024] As the alkyl group, an alkyl group having 1 to 10 carbon atoms is preferable. Specifically, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, an s-butyl group, a t-butyl group, an n-hexyl group, a 2-ethylhexyl group, an n-octyl group, an n-decyl group, etc. are preferably exemplified.

[0025] As the aryl group, an aryl group having 6 to 20 carbon atoms is preferred. Specifically, a phenyl group, o-tolyl group, m-tolyl group, p-tolyl group, 1-naphthyl group, 2-naphthyl group, etc. are preferably exemplified.

[0026] More specifically, the aromatic polysulfone has a main chain structure represented by the following formula (S-1-1).

[0027] [Chemical formula] [In the formula, R 1 and R 2 are each independently an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 20 carbon atoms. n1 and n2 are each independently an integer of 0 to 4. When n1 or n2 is 2 or more, a plurality of R 1 and R 2 may be the same as or different from each other. X is a single bond or a group derived from bisphenol or biphenol. n is an integer of 1 or more.]

[0028] The group derived from bisphenol among X is a divalent group obtained by removing hydrogen atoms from two hydroxy groups of bisphenol. Specifically, groups derived from bisphenol A: (2,2-bis(4-hydroxyphenyl)propane), bisphenol AF: 2,2-bis(4-hydroxyphenyl)hexafluoropropane, bis(4-hydroxyphenyl)sulfide, bis(4-hydroxy-3-methylphenyl)sulfide, and bis(4-hydroxyphenyl)ether are exemplified. Among them, the group derived from bisphenol A is preferred.

[0029] The group derived from biphenol among X is a divalent group obtained by removing hydrogen atoms from the two hydroxy groups of biphenol. Specifically, groups derived from 4,4'-biphenol (4,4'-dihydroxybiphenyl), 2,2'-dihydroxybiphenyl, 3,5,3',5'-tetramethyl-4,4'-dihydroxybiphenyl, 2,2'-diphenyl-4,4'-dihydroxybiphenyl, and 4,4'-dihydroxy-p-quaterphenyl are exemplified. Among them, a group derived from 4,4'-biphenol is preferred.

[0030] X is preferably a single bond.

[0031] n is preferably from 5 to 600.

[0032] (Structure of the main chain 2) The aromatic polysulfone may have a repeating unit represented by the following formula (S-2) or the following formula (S-3) in the main chain. -ph 3 -R-ph 4 -O- ···(S-2) -(ph 5 ) n -O- ···(S-3) [In formula (S-2), ph 3 and ph 4 are each independently a phenylene group which may have a substituent. R is an alkylidene group, an oxygen atom or a sulfur atom. In formula (S-3), ph 5 is a phenylene group which may have a substituent. n is an integer of 1 to 3. When n is 2 or more, a plurality of existing Ph 5 may be the same as or different from each other.]

[0033] ph 3 、ph 4 and ph 5 As, respectively, ph in formula (S-1) 1 and ph 2 include the same groups as the phenylene groups which may have substituents in.

[0034] As the above-mentioned alkylidene group, an alkylidene group having 1 to 5 carbon atoms is preferable, and examples thereof include a methylene group, an ethylidene group, an isopropylidene group, and a 1-butylidene group.

[0035] In formula (S-3), n is preferably 1 or 2.

[0036] (Structure at the main chain end) The aromatic polysulfone of the present embodiment has the above-mentioned FG at the main chain end. In the present specification, the "polar group" refers to a group containing one or more heteroatoms. Specifically, the polar group refers to one or more groups selected from the group consisting of "an acidic group having a pKa equal to or lower than that of a carboxy group" and "a salt of an acidic group having a pKa equal to or lower than that of a carboxy group" and "a functional group containing a nitrogen atom".

[0037] In the present specification, the "acidic group having a pKa equal to or lower than that of a carboxy group" is an acidic group having the property that when a compound having a carboxy group is used as a reference and the carboxy group of the compound is converted to the acidic group, the pKa of the compound having the acidic group is equal to or lower than the pKa of the compound having a carboxy group.

[0038] Specific examples of the "acidic group having a pKa equal to or lower than that of a carboxy group" in the aromatic polysulfone include a carboxy group (-COOH), a sulfonic acid group (-SO2OH), a sulfinic acid group (-SO2H), and a phosphoric acid group (H2PO4-). Among them, a sulfonic acid group is preferable.

[0039] In the present specification, the "salt of an acidic group (salt of an acidic group having a pKa equal to or lower than that of a carboxy group)" is a salt of the above-mentioned acidic group and a base (inorganic base or organic base), and is a group in which the above-mentioned acidic group and the base form a salt.

[0040] Examples of the salt of the acidic group and an inorganic base include alkali metal salts such as sodium salts and potassium salts, and ammonium salts. Examples of the salt of an acidic group and an organic base include imidazolium salts and pyridinium salts.

[0041] Examples of imidazolium salts include N,N'-dialkylimidazolium salts such as 1-methylimidazolium salt, 1-ethyl-3-methylimidazolium salt, 1-propyl-3-methylimidazolium salt, 1-methyl-3-octylimidazolium salt, 1-decyl-3-methylimidazolium salt, 1-dodecyl-3-methylimidazolium salt, 1-methyl-3-dodecylimidazolium salt, 1-tetradecyl-3-methylimidazolium salt, 1-methyl-3-tetradecylimidazolium salt, 1-hexadecyl-3-methylimidazolium salt, 1-hexadecyl-4-methylimidazolium salt, 1-methyl-3-hexadecylimidazolium salt, 1-dodecyl-2-methyl-3-benzylimidazolium salt, and the like.

[0042] Examples of pyridinium salts include N-alkylpyridinium salts such as 1-methylpyridinium salt, 1-butyl-4-methylpyridinium salt, 1-laurylpyridinium salt, 1-tetradecylpyridinium salt, 1-hexadecylpyridinium salt, 1-tetradecyl-4-methylpyridinium salt, 1-hexadecyl-4-methylpyridinium salt, and the like.

[0043] As the "salt of an acidic group" in aromatic polysulfone, a group composed of an alkali metal salt, imidazolium salt, or pyridinium salt of a carboxy group, sulfonic acid group, sulfinic acid group, or phosphoric acid group is preferred, a group composed of an alkali metal salt of a sulfonic acid group, sulfinic acid group, or phosphoric acid group is more preferred, and a group composed of an alkali metal salt of a sulfonic acid group is even more preferred.

[0044] As the "salt of an acidic group", a sodium sulfonate group (-SO2ONa) or a potassium sulfonate group (-SO2OK) is suitable.

[0045] Specific examples of the "functional group containing a nitrogen atom" in aromatic polysulfone include an amino group (-NH2) and the like.

[0046] The aromatic polysulfone may have one kind of FG alone or two or more kinds of FG. Further, the aromatic polysulfone may have any one kind of the above-described acidic group, salt of the acidic group, and functional group containing a nitrogen atom, or may have a plurality of kinds of them.

[0047] It is more preferable that the main chain terminal of the aromatic polysulfone is a terminal unit represented by the following formula (Se-1). (Ra) x -Ar-O- …(Se-1) [In the formula, Ar is an aromatic hydrocarbon group which may have a substituent. Ra is one or more polar groups selected from the group consisting of an acidic group having a pKa equal to or lower than the pKa of a carboxy group, a salt of the acidic group, and a functional group containing a nitrogen atom. x is an integer of 1 or more.]

[0048] The aromatic hydrocarbon group in Ar has at least one aromatic ring. The aromatic ring may be monocyclic or polycyclic. Further, the aromatic ring may be an aromatic heterocyclic ring.

[0049] Examples of the aromatic ring include a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, etc., and a benzene ring or a naphthalene ring is preferable.

[0050] The substituent that Ar may have is the above-described ph 1 ,ph 2 Examples of the substituent that may be had are the same alkyl groups, aryl groups, etc. as those that may be had by ph

[0051] Ra in the formula (Se-1) is the same as Ra in the above-described formula (A). Ra is preferably a sulfonic acid group or a salt of a sulfonic acid group.

[0052] The bonding position of Ra bonded to Ar is not particularly limited. When Ar is a phenylene group, it is preferable that Ra is at the meta-position or para-position with respect to the oxygen atom bonded to the phenylene group.

[0053] (Amount of FG) In this embodiment, the amount of FG of the aromatic polysulfone is determined as the amount of FG per 100 units of the repeating unit forming the main chain (FG ratio; hereinafter, may be referred to as "FG amount").

[0054] The amount of FG at the main chain end is 1 calculated from the peak area of 1H-NMR. The specific calculation method is as follows (i) to (v).

[0055] (i) For the aromatic polysulfone 1 perform 1H-NMR measurement, and from the obtained 1 1H-NMR spectrum, determine the peak area A of the hydrogen atoms contained in the repeating unit of the main chain of the aromatic polysulfone. As the peak area A, (i-1) the peak area of all hydrogen atoms contained in the repeating unit may be determined, or (i-2) only the peak area of the hydrogen atoms with an easy-to-attribute belonging among the hydrogen atoms contained in the repeating unit may be determined.

[0056] In the case of (i-2), for example, when the aromatic ring of the repeating unit is unsubstituted, the peak area of the hydrogen atom at the α-position of the sulfonyl group can be used as the peak area A. Also, when the hydrogen atoms of the aromatic ring of the repeating unit are substituted with methyl groups and the aromatic polysulfone as a whole has no other alkyl groups, the peak area of the hydrogen atoms of the methyl group can be used as the peak area A.

[0057] (ii) Divide the peak area A by the number of hydrogen atoms bonded to the aromatic ring of the main chain to calculate a value corresponding to the number of repeating units (number of units). For example, when the peak area A is the peak area attributed to 4 hydrogen atoms bonded to the aromatic ring of the main chain, divide the peak area A by 4. When the hydrogen atoms of the aromatic ring of the main chain are substituted with methyl groups and the peak area A is the peak area attributed to the hydrogen atoms of the methyl group, divide the peak area A by "3 × the number of methyl groups bonded to the aromatic ring".

[0058] (iii) The above 1From the 1H-NMR spectrum, the peak area B attributed to the α-hydrogen of Ra in the aromatic ring at the main chain end of the aromatic polysulfone is determined.

[0059] (iv) By dividing the peak area B by the number of α-hydrogens, a value corresponding to the number of aromatic rings to which Ra is bonded is calculated. For example, when the peak area B is the peak area attributed to two α-hydrogens, the peak area B is divided by 2.

[0060] (v) By dividing the value obtained in (iv) by the value obtained in (ii) and further multiplying by 100 (units), the amount of FG per 100 units of the repeating unit forming the main chain of the aromatic polysulfone can be calculated.

[0061] 1 As the measurement solvent in the 1H-NMR measurement, any deuterated solvent capable of dissolving the aromatic polysulfone may be used, and deuterated dimethyl sulfoxide is preferred. When deuterated dimethyl sulfoxide is used as the measurement solvent 1 Examples of the measurement conditions for 1H-NMR are as follows. In the NMR sample, the concentration of the aromatic polysulfone to be measured is, for example, 80 mg / mL. (Measurement conditions) Measuring device: ECZ400S (manufactured by JEOL Ltd.) Static magnetic field strength: 9.4 tesla (resonance frequency: 400 MHz ( 1 H)) Spinning: 15 Hz Repetition time: 7.2 s Number of integrations: 64 times Temperature: Room temperature Internal standard substance: Dimethyl sulfoxide

[0062] For example, when the main chain of the aromatic polysulfone is composed of a repeating unit represented by the following formula (mc-1) and the main chain end has a structure represented by the following formula (e-1), the amount of FG per 100 units of the repeating unit of the aromatic polysulfone is calculated by the following calculation method.

[0063] In the following formula, Xp is the peak area attributed to the "hydrogen atom at the α-position of the sulfonyl group" (hydrogen atom Hx) in formula (mc-1). Also, Yp is the peak area attributed to the "hydrogen atom at the α-position of the sulfonate group" (hydrogen atom Hy) in formula (e-1) (the aromatic ring at the main chain end). FG amount = [(Yp / 2) / (Xp / 4)]×100 = Yp / Xp×200

[0064] [Chemical formula]

[0065] [Chemical formula]

[0066] In the above example, it was shown that the polar group at the main chain end is a sulfonate group, but the same can be considered when the polar group at the main chain end is an amino group.

[0067] Also, when the main chain end has a structure represented by the following formula (e-2), the FG amount per 100 units of the repeating unit of the aromatic polysulfone is calculated by the following calculation method. FG amount = [Yp / (Xp / 4)]×100 = Yp / Xp×400

[0068] [Chemical formula]

[0069] [Method for producing aromatic polysulfone] In the present embodiment, the above-mentioned aromatic polysulfone is produced by reacting an aromatic polysulfone precursor and a compound having FG in the presence of at least one alkali metal salt and at least one phase transfer catalyst.

[0070] One embodiment of the method for producing an aromatic polysulfone includes a step of preparing an aromatic polysulfone precursor having a halogen atom at the main chain terminal (step (i)), reacting the aromatic polysulfone precursor with a compound having FG in the presence of at least one alkali metal salt and at least one phase transfer catalyst to produce an aromatic polysulfone having FG at the main chain terminal (step (ii)).

[0071] (Step (i)) As described above, the aromatic polysulfone precursor has a repeating unit represented by the following general formula (S-1) in the main chain and a halogen atom at the main chain terminal. -ph 1 -SO2-ph 2 -O- …(S-1)

[0072] The aromatic polysulfone precursor may be synthesized by the method described later or may be a commercially available product.

[0073] Examples of commercially available aromatic polysulfone precursors include Sumikaexcel (registered trademark) PES 3600P, 4800P, 5900P (all polyethersulfones, all manufactured by Sumitomo Chemical Co., Ltd.).

[0074] The weight average molecular weight of the aromatic polysulfone precursor is preferably from 1000 to 200000, more preferably from 8000 to 150000, and still more preferably from 10000 to 100000.

[0075] The weight average molecular weight (Mw) can be determined by gel permeation chromatography (GPC) analysis. Specifically, the weight average molecular weight of the aromatic polysulfone precursor means a value determined in terms of standard polystyrene based on a calibration curve obtained by measuring the molecular weight of standard polystyrene.

[0076] (Method for producing aromatic polysulfone precursor) The aromatic polysulfone precursor can be produced by using a halogenoaromatic sulfone compound having 2 or 3 halogen atoms bonded thereto, a dihydroxyaromatic compound, etc. as monomers and subjecting these monomers to a polycondensation reaction in an organic solvent in the presence of a base.

[0077] (Monomer) The halogenoaromatic sulfone compound is a compound having an aromatic ring, a sulfonyl group, and 2 or 3 halogen atoms bonded to the aromatic ring in one molecule. The dihydroxyaromatic compound is a compound having an aromatic ring and 2 hydroxy groups bonded to the aromatic ring in one molecule. The halogenoaromatic sulfone compound and the dihydroxyaromatic compound correspond to the repeating units constituting the aromatic polysulfone precursor.

[0078] The aromatic polysulfone precursor can be produced by using a compound represented by the following formula (mx-1) as the halogenoaromatic sulfone compound and a compound represented by the following formula (my-1) as the dihydroxyaromatic compound. X 1 -ph 1 -SO2-ph 2 -(X 2 ) m ···(mx-1) HO-ph 1 -SO2-ph 2 -OH ···(my-1) [In formula (mx-1), ph 1 and ph 2 are each independently a phenylene group which may have a substituent. X 1 and X 2 are each independently a halogen atom. m is 1 or 2. In formula (my-1), ph 1 and ph 2 are each independently a phenylene group which may have a substituent.]

[0079] Ph in formulas (mx-1) and (my-1) 1 and ph2 is the same as ph in the general formula (S-1) described above 1 and ph 2 is the same.

[0080] In formula (mx-1), X 1 and X 2 are each independently a halogen atom. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a chlorine atom is preferred.

[0081] Examples of the compound represented by formula (mx-1) include 4,4'-dichlorodiphenyl sulfone, 4,4'-difluorodiphenyl sulfone, and 4-chlorophenyl-3',4'-dichlorophenyl sulfone.

[0082] Examples of the compound represented by formula (my-1) include bis(4-hydroxyphenyl) sulfone, bis(4-hydroxy-3,5-dimethylphenyl) sulfone, and bis(4-hydroxy-3-phenylphenyl) sulfone.

[0083] When the aromatic polysulfone precursor further has a repeating unit containing the structure represented by the above formula (S-2), the compound represented by the following formula (my-2) is used as the dihydroxy aromatic compound. HO-ph 3 -R-ph 4 -OH ···(my-2) [In formula (my-2), ph 3 and ph 4 are each independently a phenylene group which may have a substituent. R is an alkylidene group, an oxygen atom or a sulfur atom.]

[0084] In formula (my-2), ph 3 , ph 4 and R are the same as ph 3 , ph 4 and R in the above formula (S-2), respectively.

[0085] Examples of the compound represented by formula (my-2) include bisphenol A: (2,2-bis(4-hydroxyphenyl)propane), bisphenol AF: 2,2-bis(4-hydroxyphenyl)hexafluoropropane, bis(4-hydroxyphenyl)sulfide, bis(4-hydroxy-3-methylphenyl)sulfide, and bis(4-hydroxyphenyl)ether, etc.

[0086] When the aromatic polysulfone precursor further has a repeating unit containing the structure represented by the above formula (S-3), as the dihydroxy aromatic compound, a compound represented by the following formula (my-3) is used. HO-(ph 5 ) n -OH ···(my-3) [In formula (my-3), ph 5 is a phenylene group which may have a substituent. n is an integer from 1 to 3. When n is 2 or more, a plurality of phs present may be the same as or different from each other.]

[0087] In formula (my-3), ph 5 and n are respectively the same as ph 5 and n in the above formula (S-3).

[0088] Examples of the compound represented by formula (my-3) include hydroquinone, resorcinol, catechol, phenylhydroquinone, 4,4'-dihydroxybiphenyl, 2,2'-dihydroxybiphenyl, 3,5,3',5'-tetramethyl-4,4'-dihydroxybiphenyl, 2,2'-diphenyl-4,4'-dihydroxybiphenyl, and 4,4'''-dihydroxy-p-quaterphenyl, etc.

[0089] In the production of the aromatic polysulfone precursor, depending on the type of the target aromatic polysulfone, both the halogeno aromatic sulfone compound and the dihydroxy aromatic compound may be used alone or in combination of two or more.

[0090] (Base, organic solvent) The polycondensation of a halogenoaromatic sulfone compound and a dihydroxyaromatic compound is preferably carried out using an alkali metal salt of carbonic acid or an alkali metal hydroxide as a base. Further, the polycondensation is preferably carried out in an organic solvent. It is more preferable that the polycondensation is carried out using an alkali metal salt of carbonic acid or an alkali metal hydroxide as a base and in an organic solvent.

[0091] Examples of the alkali metal hydroxide include potassium hydroxide, sodium hydroxide, cesium hydroxide and the like. The hydroxide may be an anhydride, a hydrate, or a mixture thereof.

[0092] The alkali metal salt of carbonic acid may be an alkali carbonate (alkali metal carbonate), a bicarbonate (alkali metal hydrogen carbonate), or a mixture thereof.

[0093] Examples of the alkali carbonate include sodium carbonate, potassium carbonate, cesium carbonate and the like. Examples of the bicarbonate include sodium bicarbonate (sodium hydrogen carbonate), potassium bicarbonate (potassium hydrogen carbonate), cesium bicarbonate (cesium hydrogen carbonate) and the like.

[0094] The organic solvent is preferably an aprotic polar solvent. The boiling point of the organic solvent is preferably 100°C or higher and 400°C or lower, and more preferably 100°C or higher and 350°C or lower.

[0095] Examples of such an organic solvent include sulfoxides such as dimethyl sulfoxide; amides such as N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone; sulfones such as sulfolane (1,1-dioxothiolane), dimethyl sulfone, diethyl sulfone, diisopropyl sulfone, diphenyl sulfone; 1,3-dimethyl-2-imidazolidinone, 1,3-diethyl-2-imidazolidinone and the like.

[0096] The organic solvent may be used alone or in combination of two or more kinds.

[0097] The polycondensation reaction temperature is preferably 180 °C or higher and 400 °C or lower, and the reaction time is preferably 4 to 10 hours.

[0098] (Step (ii)) In the present embodiment, a compound represented by the following formula (A) is used as a compound having FG (hereinafter sometimes referred to as a terminal capping agent). (Ra) x -Ar-(OM) y …(A) [In formula (A), Ar is an aromatic hydrocarbon group which may have a substituent. Ra is one or more polar groups selected from the group consisting of an acidic group having a pKa equal to or lower than the pKa of a carboxy group, a salt of the acidic group, and a functional group containing a nitrogen atom. x is an integer of 1 or more. y is 1 or 2. M is a hydrogen atom or a monovalent cation]

[0099] Ra and Ar in formula (A) are the same as Ra and Ar in the above formula (Se-1). Ra is preferably a sulfonic acid group, a salt of a sulfonic acid group or an amino group.

[0100] Examples of the cation in M include an alkali metal ion and a cation of an organic base such as an imidazolium ion or a pyridinium ion.

[0101] The terminal capping agent is not particularly limited as long as it is a compound represented by formula (A) and can introduce FG to the main chain end of the aromatic polysulfone precursor. Examples of the terminal capping agent include the following compounds and the like according to the number of Ra (x in formula (A)) possessed by the terminal capping agent.

[0102] · A terminal capping agent having one Ra 4-Hydroxybenzoic acid and its alkali metal salts 4-Hydroxybenzenesulfonic acid and its alkali metal salts 3-Hydroxybenzenesulfonic acid and its alkali metal salts 4-Hydroxybenzenesulfinic acid and its alkali metal salts 3-Hydroxybenzenesulfinic acid and its alkali metal salts (4-Hydroxyphenyl)phosphonic acid and its alkali metal salts (3-Hydroxyphenyl)phosphonic acid and its alkali metal salts 4-Aminophenol 3-Aminophenol

[0103] ·Terminal capping agent having two Ra 2-Hydroxy-6,8-naphthalenedisulfonic acid and its alkali metal salts 3-Hydroxy-2,7-naphthalenedisulfonic acid and its alkali metal salts 3-Hydroxy-2,6-naphthalenedisulfonic acid and its alkali metal salts 5-Hydroxy-1,3-benzenedisulfonic acid and its alkali metal salts 6,8-Dihydroxy-1,3-pyrenedisulfonic acid and its salts 3,6-Dihydroxy-2,7-naphthalenedisulfonic acid and its salts 2,2'-Dihydroxy-1,1'-binaphthyl-6,6'-disulfonic acid and its salts 4,5-Dihydroxy-1,3-benzenedisulfonic acid and its salts 2,4-Diaminophenol 2,5-Diaminophenol

[0104] ·Terminal capping agent having three Ra 7-Hydroxy-1,3,6-naphthalenetrisulfonic acid and its alkali metal salts

[0105] (Aprotic organic solvent) Examples of the aprotic organic solvent used in the production of the aromatic polysulfone include the aprotic polar solvents exemplified in the above (method for producing the aromatic polysulfone precursor).

[0106] (Alkali metal salt) Examples of the alkali metal salt used in the production of the aromatic polysulfone include the bases exemplified in the above (method for producing the aromatic polysulfone precursor). Preferred alkali metal salts are sodium salts, potassium salts, and cesium salts, and potassium salts are more preferred.

[0107] (Phase transfer catalyst) In the method for producing the aromatic polysulfone of the present embodiment, a phase transfer catalyst is used during the reaction between the above-described aromatic polysulfone precursor and the end-capping agent. The inventor considers the effect of the phase transfer catalyst as follows.

[0108] In the reaction between the aromatic polysulfone precursor and the end-capping agent, it is considered that the reaction occurs between the anion species of the end-capping agent generated by the reaction between the hydroxyl group of the end-capping agent and the alkali metal salt, or the anion species of the end-capping agent, and the aromatic polysulfone precursor.

[0109] At this time, if the reactivity of the end-capping agent is low, it is considered that the generation of anion species and the reaction between the anion species and the aromatic polysulfone precursor are less likely to occur, and the overall reaction is difficult to proceed. As a means of promoting the reaction, it is also conceivable to carry out the reaction at a high reaction temperature, but the energy consumption during the reaction increases, which is disadvantageous in terms of production efficiency.

[0110] On the other hand, in the method for producing an aromatic polysulfone of the present embodiment, by using a phase transfer catalyst, the reactivity of a terminal capping agent that is difficult to react is enhanced. According to the method for producing an aromatic polysulfone of the present embodiment, the aromatic polysulfone precursor and the terminal capping agent can be reacted at a relatively low temperature compared to the case where no phase transfer catalyst is used, and the energy consumption during the reaction can be suppressed. Further, since the reaction is carried out at a relatively low temperature, the selection options for the organic solvent used in the reaction and the type of heat medium used when heating the reactor increase, and the degree of freedom during production is enhanced.

[0111] Examples of the phase transfer catalyst include quaternary ammonium salts, crown ethers, and phosphonium compounds. These phase transfer catalysts may each be used alone or in combination of two or more.

[0112] (Quaternary ammonium salt) The quaternary ammonium salt is not particularly limited, but preferably, tetrabutylammonium bromide, tetrabutylammonium iodide, tetrabutylammonium 2-ethylhexanoate, tetrabutylammonium hydrogen sulfate, tetrabutylammonium chloride, tetrabutylammonium fluoride trihydrate, tetrabutylammonium nitrate, tetrabutylammonium nitrite, tetrabutylammonium acetate, tetrabutylammonium triiodide and other tetrabutylammonium salts, tetraethylammonium bromide, tetraethylammonium chloride, tetraethylammonium fluoride dihydrate and other tetraethylammonium salts, tetrapropylammonium bromide, tetrapropylammonium chloride and other tetrapropylammonium salts, tetramethylammonium chloride and other tetramethylammonium salts, benzyltriethylammonium chloride, benzyltriethylammonium bromide and other benzyltriethylammonium salts, Benzyltrimethylammonium salts such as benzyltrimethylammonium chloride, benzyltrimethylammonium bromide, and benzyltrimethylammonium dichloroiodate, benzyltributylammonium salts such as benzyltributylammonium chloride and benzyltributylammonium bromide, methyltributylammonium salts such as methyltributylammonium chloride and methyltributylammonium bromide, methyltriethylammonium salts such as methyltriethylammonium chloride and methyltriethylammonium bromide, phenyltrimethylammonium salts such as phenyltrimethylammonium chloride and at least one of them.

[0113] Further, the quaternary ammonium salt may be an ammonium salt having a linear alkyl group with more than 8 carbon atoms. As such a quaternary ammonium salt, for example, behenyl group (22 carbon atoms): behentrimonium chloride (behenyltrimethylammonium chloride), cetyl group (16 carbon atoms): cetyltrimethylammonium bromide, cetyltrimethylammonium chloride, cetyltrimethylammonium hydrogensulfate, cetalkonium chloride (benzylcetyl dimethylammonium chloride), cetalkonium bromide (benzylcetyl dimethylammonium bromide), cetyl dimethyl ethyl ammonium bromide, cetyl group (14 carbon atoms): cetrimide (myristyltrimethylammonium bromide), decyl group (10 carbon atoms): didecyldimethylammonium chloride, dodecyl group (12 carbon atoms): dodecyltrimethylammonium chloride, dodecyltrimethylammonium bromide, octyl group (8 carbon atoms): methyltrioctylammonium chloride, tetra-n-octylammonium bromide, trimethyl-n-octylammonium bromide, and trioctylmethylammonium bromide At least one kind of them is preferable.

[0114] Among these, since they are easily available, tetrabutylammonium salts are preferable, and for example, tetrabutylammonium chloride can be mentioned.

[0115] (Crown ether) There is no particular limitation on the crown ether, and it may be a crown ether in the narrow sense represented by the general structural formula (-CH2-CH2-O-) n (n is an integer), or it may be a thiacrown ether in which some or all of the oxygen atoms constituting the crown ether ring are substituted with sulfur atoms, or it may be an azacrown ether in which some or all of the oxygen atoms are substituted with NR (R is a substituent) or the like.

[0116] Also, the crown ether may be modified or may be an unmodified crown ether in the narrow sense. When the crown ether is modified, it may have a substituent on the methylene chain of the above general structural formula, or may be condensed on the methylene chain.

[0117] As the crown ether, preferably 4'-acetylbenzo-15-crown-5-ether, 4'-acetylbenzo-18-crown-6-ether, 4'-aminobenzo-15-crown-5-ether, 1-aza-12-crown-4-ether, 1-aza-15-crown-5-ether, 1-aza-18-crown-6-ether, benzo-12-crown-4-ether, benzo-15-crown-5-ether, benzo-18-crown-6-ether, bis(1,4-phenylene)-34-crown-10-ether, 4'-bromobenzo-15-crown-5-ether, 4'-bromobenzo-18-crown-6-ether, 4'-carboxybenzo-15-crown-5-ether), 4'-carboxybenzo-18-crown-6-ether, 15-Crown 4[4-(2,4-dinitrophenylazo)phenol], 18-Crown 5[4-(2,4-dinitrophenylazo)phenol], 12-Crown 4-ether, 15-Crown 5-ether, 18-Crown 6-ether, 24-Crown 8-ether, 4,10-Diaza-12-Crown 4-ether, 4,10-Diaza-15-Crown 5-ether, 4,13-Diaza-18-Crown 6-ether, Dibenzo-15-Crown 5-ether, Dibenzo-18-Crown 6-ether, Dibenzo-21-Crown 7-ether, Dibenzo-24-Crown 8-ether, Dibenzo-30-Crown 10-ether, N,N’-Dibenzyl-4,13-Diaza-18-Crown 6-ether, Dicyclohexano-18-Crown 6-ether, 4’-Formylbenzo-15-Crown 5-ether, 4’-Formylbenzo-18-Crown 6-ether, 1,4,7,10,13,16-Hexaazacyclooctadecane, 1,4,7,10,13,16-Hexaazacyclooctadecane hexahydrochloride, 4,7,13,16,21,24-Hexaoxa-1,10-diazabicyclo[8.8.8]hexacosane, 2-(Hydroxymethyl)-12-Crown 4-ether, 2-(Hydroxymethyl)-15-Crown 5-ether, 2-(Hydroxymethyl)-18-Crown 6-ether, 4’-Methoxycarbonylbenzo-15-Crown 5-ether, 4’-Nitrobenzo-15-Crown 5-ether, 4’-Nitrobenzo-18-Crown 6-ether, N-Phenylaza-15-Crown 5-ether, 1,4,7,10-Tetraazacyclododecane, 1,4,7,10-Tetraazacyclododecane-1,4,7,10-tetraacetic acid, 1,4,7,10-Tetraazacyclododecane tetrahydrochloride, 1,4,8,12 - Tetraazacyclopentadecane, 1,4,8,11 - tetraazacyclotetradecane, 1,4,7,10 - Tetrabenzyl - 1,4,7,10 - tetraazacyclododecane, Tetraethyl - 1,4,8,11 - tetraazacyclotetradecane - 1,4,8,11 - tetraaacetate, 1,4,8,11 - Tetramethyl - 1,4,8,11 - tetraazacyclotetradecane, 1,4,8,11 - tetrathia - cyclotetradecane, 1,5,9 - Triazacyclododecane, 1,4,7 - Triazacyclononane, 1,4,7 - triazacyclononane trihydrochloride, Tri - tert - butyl - 1,4,7,10 - tetraazacyclododecane - 1,4,7,10 - tetraacetate, tri - tert - butyl - 1,4,7,10 - tetraazacyclododecane - 1,4,7 - triacetate, 1,4,7 - Trimethyl - 1,4,7 - triazacyclononane (stabilized with NaHCO3), 1,4,7 - Trithia - cyclononane, is at least one of the following.

[0118] More preferably as the crown ether, 18 - crown - 6 - ether, 4,13 - diaza - 18 - crown - 6 - ether, 15 - crown - 5 - ether, 24 - crown - 8 - ether can be mentioned. As the crown ether, it is preferable to use one having a ring of an appropriate size according to the ionic radius of the metal ion constituting the alkali metal salt to be used. When using a potassium salt as the alkali metal salt, 18 - crown - 6 - ether is preferable.

[0119] (Phosphonium compound) Examples of the phosphonium compound include quaternary phosphonium salts such as tetraphenylphosphonium bromide, tributylhexadecylphosphonium bromide, tributyldodecylphosphonium bromide.

[0120] The amount of the phase transfer catalyst is preferably 10 mol% or more and 1000 mol% or less, more preferably 55 mol% or more and 800 mol% or less, and even more preferably 85 mol% or more and 750 mol% or less, based on the alkali metal salt used. The upper limit and the lower limit of the amount of the phase transfer catalyst can be arbitrarily combined.

[0121] The reaction temperature in the step of reacting the aromatic polysulfone precursor with the end-capping agent is preferably 150°C or more and less than 200°C, more preferably 130°C or more and 190°C or less, and even more preferably 150°C or more and 180°C or less.

[0122] The reaction time of the above step is preferably 4 to 15 hours.

[0123] The amount of the end-capping agent used in the above step is preferably 0.1 to 50 parts by mass, more preferably 0.6 to 25 parts by mass, based on 100 parts by mass of the aromatic polysulfone precursor.

[0124] The amount of the alkali metal salt used in the above step is preferably 0.3 to 30 parts by mass, more preferably 0.4 to 10 parts by mass, based on 100 parts by mass of the aromatic polysulfone precursor.

[0125] In addition to the above-mentioned aromatic polysulfone precursor, end-capping agent, alkali metal salt, phase transfer catalyst, etc., a halogenoaromatic sulfone compound or a dihydroxyaromatic compound may be added as an optional component in this reaction. As the halogenoaromatic sulfone compound, the compounds exemplified by the above formula (mx-1) can be used. As the dihydroxyaromatic compound, the compounds exemplified by the above formula (my-1) can be used.

[0126] According to the method for producing an aromatic polysulfone having the above configuration, an aromatic polysulfone having a polar group introduced therein can be easily produced.

[0127] As described above, the preferred embodiments of the present invention have been explained, but the present invention is not limited to such examples. Combinations of the respective configurations shown in the above examples are merely examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.

Example

[0128] The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

[0129] In this example, the following raw materials and reagents were used.

[0130] · Polyethersulfone (PES) PES1: Manufactured by Sumitomo Chemical Co., Ltd., Sumikaexcel PES 3600P PES2: Manufactured by Sumitomo Chemical Co., Ltd., Sumikaexcel PES 5900P

[0131] · End capping agent Capping agent 1: Sodium 4-hydroxybenzenesulfonate (manufactured by Tokyo Chemical Industry Co., Ltd.) Capping agent 2: Dipotassium 2-hydroxy-6,8-naphthalenedisulfonate (manufactured by Tokyo Chemical Industry Co., Ltd.) Capping agent 3: 4-aminophenol (manufactured by Tokyo Chemical Industry Co., Ltd.)

[0132] By using capping agent 1, one salt-type sulfonic acid group containing a sodium sulfonate group and a potassium sulfonate group is introduced at the main chain end of the aromatic polysulfone. That is, when capping agent 1 is used, ideally, two salt-type sulfonic acid groups, each containing a sodium sulfonate group and a potassium sulfonate group, are introduced, one at each end of the main chain of the aromatic polysulfone.

[0133] By using the capping agent 2, two salt-type sulfonic acid groups containing potassium sulfonate groups are introduced at one end of the main chain of the aromatic polysulfone. That is, when the capping agent 2 is used, ideally, two salt-type sulfonic acid groups containing sodium sulfonate groups and potassium sulfonate groups are introduced at both ends of the main chain of the aromatic polysulfone, for a total of four.

[0134] By using the capping agent 3, an amino group is introduced at one end of the main chain of the aromatic polysulfone. That is, when the capping agent 3 is used, ideally, one amino group is introduced at both ends of the main chain of the aromatic polysulfone, for a total of two.

[0135] ·Phase transfer catalyst Catalyst 1: 18-crown-6-ether (manufactured by Tokyo Chemical Industry Co., Ltd.) Catalyst 2: 4,13-diaza-18-crown-6-ether (manufactured by Tokyo Chemical Industry Co., Ltd.) Catalyst 3: 15-crown-5-ether (manufactured by Tokyo Chemical Industry Co., Ltd.) Catalyst 4: Tetrabutylammonium chloride (manufactured by Tokyo Chemical Industry Co., Ltd.)

[0136] ·Alkali metal salt K2CO3: Potassium carbonate

[0137] ·Solvent NMP: N-Methyl-2-pyrrolidone DMAc: N,N-Dimethylacetamide

[0138] ·Dihalogeno aromatic sulfone compound DCDPS: 4,4’-Dichlorodiphenyl sulfone DFDPS: 4,4’-Difluorodiphenyl sulfone

[0139] [Example 1] Into a polymerization tank equipped with a stirrer, a nitrogen inlet tube, a thermometer, and a condenser with a receiver at the tip, PES1 (100 g), capping agent 1 (4.06 g), K2CO3 (1.79 g), DCDPS (1.80 g), catalyst 1 (5.00 g) and NMP (150 g) were added and mixed. The resulting mixture was heated at 150 °C and reacted for 15 hours.

[0140] Next, the obtained reaction solution was cooled to room temperature (25 °C) to precipitate unreacted potassium carbonate and by-produced potassium chloride. The reaction solution (slurry) in which the salt had precipitated was dropped into water to precipitate aromatic polysulfone, and unnecessary NMP was removed by filtration to obtain a precipitate.

[0141] The obtained precipitate was carefully washed repeatedly with methanol and water and dried by heating at 150 °C to obtain aromatic polysulfone 1 having a polar group derived from capping agent 1 at the main chain end.

[0142] [Example 2] Aromatic polysulfone 2 was obtained in the same manner as in Example 1, except that 3.00 g of catalyst 1 was used.

[0143] [Example 3] Aromatic polysulfone 3 was obtained in the same manner as in Example 1, except that 2.00 g of catalyst 1 was used.

[0144] [Example 4] Aromatic polysulfone 4 was obtained in the same manner as in Example 1, except that 23.0 g of catalyst 1 was used.

[0145] [Example 5] Aromatic polysulfone 5 was obtained in the same manner as in Example 1, except that PES2 was used instead of PES1 and 2.48 g of DCDPS was used.

[0146] [Example 6] Aromatic polysulfone 6 was obtained in the same manner as in Example 2, except that PES2 was used instead of PES1 and 2.48 g of DCDPS was used.

[0147] [Example 7] Aromatic polysulfone 7 was obtained in the same manner as in Example 4, except that PES2 was used instead of PES1 and 2.48 g of DCDPS was used.

[0148] [Example 8] Aromatic polysulfone 8 was obtained in the same manner as in Example 1, except that DMAc was used instead of NMP.

[0149] [Example 9] Aromatic polysulfone 9 was obtained in the same manner as in Example 1, except that 1.59 g of DFDPS was used instead of DCDPS.

[0150] [Example 10] Aromatic polysulfone 10 was obtained in the same manner as in Example 9, except that PES2 was used instead of PES1 and 2.19 g of DFDPS was used.

[0151] [Example 11] Aromatic polysulfone 11 was obtained in the same manner as in Example 10, except that 3.00 g of Catalyst 1 was used.

[0152] [Example 12] Aromatic polysulfone 12 was obtained in the same manner as in Example 10, except that 23.0 g of Catalyst 1 was used.

[0153] [Example 13] Aromatic polysulfone 13 was obtained in the same manner as in Example 1, except that 8.90 g of Catalyst 2 was used instead of Catalyst 1.

[0154] [Example 14] Aromatic polysulfone 14 was obtained in the same manner as in Example 1, except that 15.0 g of Catalyst 3 was used instead of Catalyst 1.

[0155] [Example 15] Aromatic polysulfone 15 was obtained in the same manner as in Example 1, except that 5.25 g of Catalyst 4 was used instead of Catalyst 1.

[0156] [Example 16] Aromatic polysulfone 16 was obtained in the same manner as in Example 15, except that 1.59 g of DFDPS was used instead of DCDPS.

[0157] [Example 17] Aromatic polysulfone 17 was obtained in the same manner as in Example 1, except that 7.90 g of capping agent 2 was used instead of capping agent 1, the reaction temperature was changed to 180 °C, and the reaction time was changed to 10 hours.

[0158] [Example 18] Aromatic polysulfone 18 was obtained in the same manner as in Example 1, except that 2.26 g of capping agent 3 was used instead of capping agent 1 and the reaction time was changed to 8 hours.

[0159] [Comparative Example 1] Aromatic polysulfone C1 was obtained in the same manner as in Example 1, except that no phase transfer catalyst was added.

[0160] [Comparative Example 2] Aromatic polysulfone C2 was obtained in the same manner as in Example 5, except that no phase transfer catalyst was added.

[0161] [Comparative Example 3] Aromatic polysulfone C3 was obtained in the same manner as in Example 17, except that no phase transfer catalyst was added and the reaction temperature was changed to 200 °C.

[0162] [Calculation of the amount of FG per 100 units of the repeating unit of aromatic polysulfone] For the aromatic polysulfones obtained in the examples and comparative examples, a sample was prepared by dissolving the aromatic polysulfone to be measured in deuterated dimethyl sulfoxide so that the concentration of the aromatic polysulfone to be measured was 80 mg / ml, and 1 1H-NMR was measured under the following measurement conditions. (Measurement conditions) Measuring device: ECZ400S (manufactured by JEOL) Static magnetic field strength: 9.4 tesla (resonance frequency: 400 MHz ( 1 1H)) Spinning: 15 Hz Repeating time: 7.2 s Number of integrations: 64 times Temperature: 25 °C Chemical shift standard substance: Dimethyl sulfoxide

[0163] From the obtained NMR spectrum, the following two peak areas were determined. Xp: Peak area attributed to the "hydrogen atom at the α-position of the sulfonyl group" in the general formula (S-1) above. Integration value of 7.17 to 7.34 ppm. Yp: Peak area attributed to the "hydrogen atom at the α-position of the sulfonate group or amino group" in the aromatic ring at the main chain end of the aromatic polysulfone. When using Cap Agent 1 as the end-capping agent, the integration value of 7.00 to 7.07 ppm. When using Cap Agent 2 as the end-capping agent, the integration value of 8.48 to 8.53 ppm. When using Cap Agent 3 as the end-capping agent, the integration value of 6.72 to 6.84 ppm.

[0164] Using the obtained peak areas, the FG amount was calculated based on the following formulas (a1) and (a2). · When using Cap Agent 1 or Cap Agent 3 as the end-capping agent FG amount = [(Yp / 2) / (Xp / 4)] × 100 = Yp / Xp × 200 …(a1) · When using Cap Agent 2 as the end-capping agent FG amount = [Yp / (Xp / 4)] × 100 = Yp / Xp × 400 …(a2)

[0165] The results are shown in Table 1 below. In Table 1, the "addition amount" of the phase transfer catalyst indicates the ratio (mol%) to the potassium carbonate used.

[0166]

Table 1

[0167] In Examples 1 to 18, it was confirmed that the amount of FG was large compared to Comparative Examples 1 to 3, and a large amount of FG was introduced at the main chain terminals.

[0168] From the above results, it was confirmed that the present invention is useful.

Claims

1. A process of reacting an aromatic polysulfone precursor with at least one compound represented by the following formula (A), The aromatic polysulfone precursor has a repeating unit containing a structure represented by the following general formula (S-1) in the main chain and a halogen atom at the main chain terminal, The process is a method for producing an aromatic polysulfone carried out in the presence of at least one alkali metal salt and at least one phase transfer catalyst in an aprotic organic solvent. -ph １ -SO ２ -ph ２ -O- …(S-1) [In formula (S-1), ph １ and ph ２ are each independently a phenylene group which may have a substituent.] (Ra) ｘ -Ar-OM …(A) [In formula (A), Ar is an aromatic hydrocarbon group which may have a substituent. Ra is one or more polar groups selected from an acidic group having a pKa equal to or lower than the pKa of a carboxy group, a salt of the acidic group, and a functional group containing a nitrogen atom. x is an integer of 1 or more. M is a hydrogen atom or a monovalent cation]

2. The method for producing an aromatic polysulfone according to claim 1, wherein the amount of the phase transfer catalyst is 10 mol% or more and 1000 mol% or less based on the alkali metal salt.

3. The method for producing an aromatic polysulfone according to claim 1 or 2, wherein the reaction temperature of the process is 130°C or higher and lower than 200°C.

4. The method for producing an aromatic polysulfone according to claim 1 or 2, wherein the phase transfer catalyst is 18-crown-6-ether.

5. The method for producing an aromatic polysulfone according to claim 1 or 2, wherein the alkali metal salt is a potassium salt. Claim 6 The method for producing an aromatic polysulfone according to claim 1 or 2, wherein Ra is a sulfonic acid group, a salt of a sulfonic acid group or an amino group. Claim 7 The method for producing an aromatic polysulfone according to claim 1 or 2, wherein Ra is a sulfonic acid group or a salt of a sulfonic acid group.

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