Aromatic polysulfone, resin composition, and method for producing aromatic polysulfone

Abstract

An aromatic polysulfone which has, at main-chain ends, functional groups of one or more kinds selected from the group consisting of acidic groups having a pKa not higher than the pKa of the carboxyl group and salts of said acidic groups, wherein the amount of the functional groups, as calculated from 1H-NMR peak area ratios, is 0.35-40 per 100 repeating units constituting the main chain of the aromatic polysulfone.

Description

[Technical Field]

[0001] The present invention relates to aromatic polysulfones, resin compositions, and methods for producing aromatic polysulfones. This application claims priority based on Japanese Patent Application No. 2020-213943, filed in Japan on December 23, 2020, and the contents of that application are incorporated herein by reference. [Background technology]

[0002] Aromatic polysulfones possess excellent heat resistance, mechanical properties, electrical properties, and hot water resistance. Therefore, aromatic polysulfones are used in numerous applications, including in the electrical and electronic, mechanical, automotive, aerospace, and medical / food industries. Furthermore, depending on the application, hydrophilic aromatic polysulfones may be required. Examples of the hydrophilized aromatic polysulfone include aromatic polysulfones having polar groups.

[0003] Patent Document 1 proposes an internal pressure type hollow fiber NF membrane using sulfonated polyethersulfone. Patent Document 1 discloses an internal pressure type hollow fiber NF membrane comprising a mixture containing sulfonated polyethersulfone and polyethersulfone, wherein the content ratio of sulfonated polyethersulfone to polyethersulfone in the total amount of sulfonated polyethersulfone is 20-50% by mass of sulfonated polyethersulfone and 80-50% by mass of polyethersulfone, and the degree of sulfonation of sulfonated polyethersulfone is 0.10-0.18. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2013-215640 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] When aromatic polysulfone is used as a material for forming a separation membrane, the separation membrane formed from the aromatic polysulfone is required to have higher water permeability and higher mechanical strength.

[0006] The present invention has been made in view of the above circumstances, and aims to provide an aromatic polysulfone useful as a material for forming separation membranes, a resin composition containing the aromatic polysulfone, and a method for producing the aromatic polysulfone. [Means for solving the problem]

[0007] As a result of diligent research to solve the above problems, the present inventors have found that by introducing one or more functional groups selected from the group consisting of acidic groups having a specific acidity and salts of said acidic groups to the main chain end of an aromatic polysulfone, and by setting the amount of said functional group within a specific range, an aromatic polysulfone useful as a material for forming separation membranes can be obtained, thus completing the present invention.

[0008] In other words, the present invention has the following aspects. [1] An aromatic polysulfone having one or more functional groups selected from the group consisting of an acidic group having a pKa less than or equal to the pKa of a carboxyl group and a salt of the acidic group at the main chain terminus, 1 An aromatic polysulfone in which the amount of the functional group, calculated from the peak area ratio of the 1H-NMR spectrum, is 0.35 to 40 per 100 repeating units forming the main chain of the aromatic polysulfone. [2] The aromatic polysulfone according to [1], which has repeating units containing a structure represented by the following general formula (S-1) and terminal units represented by the following general formula (Se-1). -ph 1 -SO2-ph 2 -O- ···(S-1) -ph 1 -SO2-ph 2 -O-Ar-Ra ···(Se-1) [In the formula, ph1 and ph 2 Each of these is independently a phenylene group which may have substituents. Ar is an aromatic hydrocarbon group which may have substituents. Ra is one or more functional groups selected from the group consisting of acidic groups having a pKa less than or equal to that of a carboxyl group and salts of said acidic groups. [3] The aromatic polysulfone according to [1] or [2], wherein the amount of the functional group is 0.7 to 40 per 100 repeating units. [4] The aromatic polysulfone according to any one of [1] to [3], which is a mixed resin of an aromatic polysulfone having the functional group at the end of the main chain and an aromatic polysulfone not having the functional group at the end of the main chain. A resin composition comprising an aromatic polysulfone described in any one of items [5][1] to [4] and a filler. A method for producing aromatic polysulfone according to any one of items [6][1] to [3], A method for producing an aromatic polysulfone, comprising the step of reacting an aromatic polysulfone precursor having a halogen atom at the main chain terminus with a compound having the functional group to produce an aromatic polysulfone having the functional group at the main chain terminus. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide an aromatic polysulfone useful as a material for forming separation membranes, a resin composition containing the aromatic polysulfone, and a method for producing the aromatic polysulfone. [Modes for carrying out the invention]

[0010] (Aromatic polysulfone) The aromatic polysulfone of this embodiment is an aromatic polysulfone having one or more functional groups (hereinafter also referred to as FG) selected from the group consisting of an acidic group having a pKa less than or equal to the pKa of a carboxyl group and a salt of the acidic group at the end of the main chain, 1 The amount of functional groups, calculated from the peak area ratio of 1H-NMR, is 0.35 to 40 per 100 repeating units forming the main chain of the aromatic polysulfone.

[0011] The aromatic polysulfone of this embodiment is typically a resin having a repeating unit containing a divalent aromatic group (a residue obtained by removing two hydrogen atoms bonded to the aromatic ring from an aromatic compound), a sulfonyl group (-SO2-), and an oxygen atom (-O-), and having the above FG at the main chain terminal. Further, the divalent aromatic group may have a substituent, and typical examples of the substituent include an alkyl group or an aryl group.

[0012] The aromatic polysulfone of this embodiment preferably has a repeating unit containing a structure represented by the following formula (S-1). -ph 1 -SO2-ph 2 -O- ···(S-1)<完了>0000216[In the formula, ph 1 and ph 2 are each independently a phenylene group which may have a substituent.]<00002成績17>成績

[0013] ph 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.

[0014] Examples of the substituent that the above phenylene group may have include an alkyl group, an aryl group, and the like. As the alkyl group, an alkyl group having 1 to 10 carbon atoms is preferable, and 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. As the aryl group, an aryl group having 6 to 20 carbon atoms is preferable, and specifically, a phenyl group, an o-tolyl group, an m-tolyl group, a p-tolyl group, a 1-naphthyl group, a 2-naphthyl group, etc. are preferably exemplified.

[0015] The aromatic polysulfone of this embodiment may include repeating units that, in addition to the structure represented by formula (S-1) above, include the structure represented by the following formula (S-2) or the structure represented by the following formula (S-3). -ph 3 -R-ph 4 -O- ···(S-2) -(ph 5 ) n -O- ···(S-3) [In formula (S-2), ph 3 and ph 4 Each of these is independently a phenylene group which may have substituents. 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 substituents. n is an integer from 1 to 3. If n is 2 or greater, there are multiple Ph groups. 5 They may be the same or different from each other.

[0016] ph 3 ph 4 and ph 5 For each of them, the ph in equation (S-1) 1 and ph 2 Examples include phenylene groups that may have substituents, similar to those in the example above.

[0017] The alkylidene group mentioned above is preferably an alkylidene group having 1 to 5 carbon atoms, and examples include a methylene group, an ethylidene group, an isopropylidene group, and a 1-butylidene group.

[0018] In formula (S-3), n is preferably 1 or 2.

[0019] The aromatic polysulfone of this embodiment has one or more functional groups selected from the group consisting of an acidic group having a pKa less than or equal to that of a carboxyl group and a salt of the acidic group at the end of the main chain. In this specification, “an acidic group having a pKa less than or equal to the pKa of a carboxyl group” means an acidic group that, when the carboxyl group of a compound having a carboxyl group is converted to the acidic group, the pKa of the compound having the acidic group becomes less than or equal to the pKa of the compound having the carboxyl group.

[0020] For example, if the main chain terminal of the aromatic polysulfone in this embodiment is a terminal structure derived from 4-hydroxybenzoic acid, then "an acidic group having a pKa less than or equal to the pKa of the carboxyl group" means an acidic group having the characteristic that when the carboxyl group of 4-hydroxybenzoic acid is converted to the acidic group, the pKa of the aqueous solution of the compound obtained by converting the carboxyl group of 4-hydroxybenzoic acid to the acidic group at 25°C is less than or equal to the pKa of the carboxyl group of 4-hydroxybenzoic acid, i.e., 4.47.

[0021] In this embodiment, the "acidic group having a pKa less than or equal to that of the carboxyl group" in the aromatic polysulfone specifically includes carboxyl groups (-COOH), sulfonic acid groups (-SO2OH), sulfinic acid groups (-SO2H), phosphate groups (H2PO4-), and the like.

[0022] Furthermore, in this specification, “the salt of the acidic group (a salt of an acidic group having a pKa less than or equal to the pKa of the carboxyl group)” refers to a group consisting of a salt of the above-mentioned acidic group with an inorganic base or an organic base. Specifically, it refers to a group in which the hydrogen cation of the acidic group is replaced with a cation of another atom or a molecule having a cation.

[0023] Examples of salts of the acidic group and inorganic base include alkali metal salts such as sodium salts and potassium salts; and ammonium salts. Examples of salts of the aforementioned acidic group with an organic base include imidazolium salts and pyridinium salts.

[0024] 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, and 1-dodecyl-2-methyl-3-benzylimidazolium salt.

[0025] 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, and 1-hexadecyl-4-methylpyridinium salt.

[0026] In the aromatic polysulfone of this embodiment, the "salt of the acidic group" is preferably a group consisting of an alkali metal salt, imidazolium salt, or pyridinium salt of a carboxyl group (-COOH), a sulfonic acid group (-SO2OH), a sulfinic acid group (-SO2H), or a phosphate group (H2PO4-), more preferably a group consisting of an alkali metal salt of a sulfonic acid group (-SO2OH), a sulfinic acid group (-SO2H), or a phosphate group (H2PO4-), and even more preferably a group consisting of an alkali metal salt of a sulfonic acid group (-SO2OH). Sodium sulfonate group (-SO2ONa) or potassium sulfonate group (-SO2OK) are suitable.

[0027] In this embodiment, the FG in the aromatic polysulfone is preferably a group represented by any of the following formulas (Ra-1) to (Ra-4), with the group represented by formula (Ra-1) being preferred.

[0028] [ka] [In equations (Ra-1) to (Ra-4), Z 1 ~Z 5 Each of these is independently a hydrogen atom, an alkali metal atom, an imidazole group, or a pyridine group. * indicates a bond.

[0029] In equations (Ra-1) to (Ra-4), Z 1 ~Z 5 In this mixture, sodium atoms or potassium atoms are preferred as alkali metal atoms.

[0030] In equations (Ra-1) to (Ra-4), Z 1 ~Z 5 The imidazole group in this context is a group obtained by removing one hydrogen atom from an imidazole compound. Specific examples of imidazole compounds include N,N′-dialkylimidazoles such as 1-methyl-3-octylimidazole, 1-decyl-3-methylimidazole, 1-dodecyl-3-methylimidazole, 1-methyl-3-dodecylimidazole, 1-tetradecyl-3-methylimidazole, 1-methyl-3-tetradecylimidazole, 1-hexadecyl-3-methylimidazole, 1-hexadecyl-4-methylimidazole, 1-methyl-3-hexadecylimidazole, and 1-dodecyl-2-methyl-3-benzylimidazole.

[0031] In equations (Ra-1) to (Ra-4), Z 1 ~Z 5 The pyridine group in this context is a pyridine compound with one hydrogen atom removed. Specific examples of pyridine compounds include N-alkylpyridines such as 1-laurylpyridine, 1-tetradecylpyridine, 1-hexadecylpyridine, 1-tetradecyl-4-methylpyridine, and 1-hexadecyl-4-methylpyridine.

[0032] In equations (Ra-1) to (Ra-4), Z 1 ~Z 5Each of these atoms is preferably a hydrogen atom or an alkali metal atom, more preferably a hydrogen atom, a sodium atom, or a potassium atom, and even more preferably a sodium atom.

[0033] The aromatic polysulfone of this embodiment may have one FG, or two or more FGs, and may have either an acidic group having a pKa less than or equal to the pKa of the carboxyl group, or a salt of the acidic group, or may have only one of the acidic group or a salt of the acidic group.

[0034] The aromatic polysulfone of this embodiment has repeating units including the structure represented by the above formula (S-1), and it is more preferable that the main chain end of the aromatic polysulfone is a terminal unit represented by the following formula (Se-1). -ph 1 -SO2-ph 2 -O-Ar-Ra ···(Se-1) [In the formula, ph 1 and ph 2 Each of these is independently a phenylene group which may have substituents. Ar is an aromatic hydrocarbon group which may have substituents. Ra is one or more functional groups selected from the group consisting of acidic groups having a pKa less than or equal to that of a carboxyl group and salts of said acidic groups.

[0035] In formula (Se-1), ph 1 and ph 2 These are, independently of each other, the ph in equation (S-1) as described above. 1 and ph 2 These are identical to the phenylene groups in which substituents may be present.

[0036] In formula (Se-1), the aromatic hydrocarbon group in Ar is a hydrocarbon group having at least one aromatic ring. This aromatic ring is not limited to a cyclic conjugated system with 4n+2 π electrons, and may be monocyclic or polycyclic, or it may be an aromatic heterocycle in which some of the carbon atoms constituting the ring are substituted with heteroatoms. Examples of aromatic rings in the aromatic hydrocarbon group include benzene rings, naphthalene rings, anthracene rings, and phenanthrene rings, with benzene rings being preferred among them. In other words, the aromatic hydrocarbon group in Ar is preferably a phenylene group.

[0037] In formula (Se-1), Ra is one or more functional groups selected from the group consisting of acidic groups having a pKa less than or equal to the pKa of a carboxyl group and salts of said acidic groups, as detailed above. In formula (Se-1), the Ra bonded to Ar may be a single element or two or more elements. Furthermore, the bonding position of the Ra bonded to Ar is not particularly limited, but for example, if Ar is a phenylene group, it is preferable to have the Ra at position 3 or 4, with the bond position to the oxygen atom of the phenylene group being position 1.

[0038] The aromatic polysulfone of this embodiment is more preferably an aromatic polysulfone S1 (hereinafter also referred to as "aromatic polysulfone S1") having repeating units represented by the following formula (S-1-1) and terminal units represented by the following formula (Se-1-1).

[0039] [ka] [In the formula, R 1 and R 2 Each is independently an alkyl group having 1 to 10 carbon atoms, or an aryl group having 6 to 20 carbon atoms. n1 and n2 are independently integers from 0 to 4, and if n1 or n2 is 2 or more, multiple R 1 and R 2 The groups may be identical or different. X is a single bond or a group derived from bisphenol or biphenol. n is an integer greater than or equal to 1.

[0040] [ka] [In the formula, Ra is one or more functional groups selected from the group consisting of acidic groups having a pKa less than or equal to the pKa of a carboxyl group and salts of said acidic groups. Ar is an aromatic hydrocarbon group which may have substituents. R 1 and R 2 Each is independently an alkyl group having 1 to 10 carbon atoms, or an aryl group having 6 to 20 carbon atoms. n1 and n2 are independently integers from 0 to 4, and if n1 or n2 is 2 or more, multiple R 1 and R 2 The elements may be identical or different. * indicates a bonding action.

[0041] R in equations (S-1-1) and (Se-1-1) 1 and R 2 The alkyl group having 1 to 10 carbon atoms and the aryl group having 6 to 20 carbon atoms in formula (S-1) are the pH groups in formula (S-1). 1 and ph 2 Examples of substituents that the phenylene group may have are similar to those exemplified above. In formulas (S-1-1) and (Se-1-1), n1 and n2 are each independently preferably 0 to 2, more preferably 0 to 1, and even more preferably 0.

[0042] Specifically, the groups derived from bisphenol are divalent groups obtained by removing one hydroxyl group and the hydrogen atom of the other hydroxyl group from the two hydroxyl groups of bisphenol. Specifically, these include 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) ethers, respectively. Among these, the groups derived from bisphenol A, i.e., the divalent groups obtained by removing one hydroxyl group and the hydrogen atom of the other hydroxyl group from the two hydroxyl groups of bisphenol A, are preferred.

[0043] Examples of groups derived from biphenols include those 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, respectively. The group derived from 4,4'-biphenol, that is, a divalent group obtained by removing one hydroxyl group and the hydrogen atom of the other hydroxyl group of 4,4'-biphenol, is preferred.

[0044] X is preferably a single bond.

[0045] n is preferably between 5 and 600.

[0046] In equation (Se-1-1), Ar is the same as Ar in equation (Se-1).

[0047] In formula (Se-1-1), Ra is one or more functional groups selected from the group consisting of acidic groups having a pKa less than or equal to the pKa of a carboxyl group and salts of said acidic groups, as detailed above.

[0048] [Amount of FG] The aromatic polysulfone of this embodiment is an aromatic polysulfone having FG at the end of its main chain, 1 The amount of FG at the main chain terminus, calculated from the peak area ratio of 1H-NMR, is 0.35 to 40 per 100 repeating units forming the main chain of aromatic polysulfone.

[0049] In the aromatic polysulfone of this embodiment, 1 The amount of FG at the main chain terminus, calculated from the peak area ratio of 1H-NMR, is 0.35 or more per 100 repeating units forming the main chain of the aromatic polysulfone, preferably 0.5 or more, more preferably 0.65 or more, even more preferably 0.7 or more, particularly preferably 1.3 or more, and most preferably 1.5 or more. The amount of FG at the main chain terminus is 40 or less per 100 repeating units forming the main chain of the aromatic polysulfone, preferably 10 or less, more preferably 7 or less, even more preferably 5 or less, particularly preferably 3 or less, and most preferably 2.5 or less.

[0050] In the aromatic polysulfone of this embodiment, 1 The amount of FG at the main chain terminus, calculated from the peak area ratio of 1H-NMR, is preferably 0.5 to 40, more preferably 0.5 to 10, even more preferably 0.7 to 10, even more preferably 0.7 to 7, even more preferably 0.7 to 5, particularly preferably 1.5 to 3, and most preferably 1.3 to 2.5. It may also be 0.5 to 7.

[0051] In the aromatic polysulfone of this embodiment, if the amount of FG at the end of the main chain is 0.5 or more per 100 repeating units forming the main chain of the aromatic polysulfone, the water permeability of the separation membrane formed from the aromatic polysulfone is good. If the amount of FG is 0.65 or more, the water permeability of the separation membrane formed from the aromatic polysulfone is improved, and the fouling resistance is also improved. Here, fouling means an irreversible decrease in membrane performance, for example, the occurrence of blockage (clogging) of the separation membrane. If the amount of FG at the main chain terminals is 40 or less, the separation membrane containing the thin film formed from the aromatic polysulfone has good mechanical strength.

[0052] The amount of FG at the main chain terminus of aromatic polysulfone 1 It is calculated by 1H-NMR measurement. The specific calculation method is as follows: (i) In the repeating units of the main chain of an aromatic polysulfone, the peak area A that is attributed to the hydrogen atoms bonded to the aromatic ring of the main chain whose number of hydrogen atoms is already known is: 1 It is determined by measuring 1H-NMR. (ii) The number of repeating units can be calculated by dividing the peak area A by the number of hydrogen atoms bonded to the aromatic ring of the main chain (for example, if the peak area A is the peak area attributed to the four hydrogen atoms bonded to the aromatic ring of the main chain, divide by 4). (iii) The peak area B that is attributed to the hydrogen atom bonded to the carbon atom adjacent to the carbon atom to which FG is bonded in the aromatic ring at the end of the main chain of the aromatic polysulfone is 1 It is determined by measuring 1H-NMR. (iv) The number of FGs can be calculated by dividing the peak area B by the number of hydrogen atoms bonded to carbon atoms adjacent to the carbon atom to which FG is bonded (for example, if the peak area B is the peak area attributed to the two hydrogen atoms bonded to carbon atoms adjacent to the carbon atom to which FG is bonded, divide by 2). By dividing the number of FG obtained in (v) and (iv) by the number of repeating units (units) obtained in (ii), and then multiplying by 100 (100 units), the amount of FG per 100 repeating units forming the main chain of the aromatic polysulfone can be calculated.

[0053] 1 As for the solvent used in H-NMR measurements, 1 Any solvent capable of 1H-NMR measurement and dissolving aromatic polysulfones is acceptable; deuterated dimethyl sulfoxide is preferred. When didimethyl sulfoxide is used as the measurement solvent: 1 The following conditions can be used for measuring H-NMR. [solution 1 [Measurement conditions for H-NMR] Measurement device: ECZ400S (manufactured by JEOL) Static magnetic field strength: 9.4 Tesla (Resonance frequency: 400 MHz) 1 H)) Spinning frequency: 15Hz Repeat time: 7.2s Total number of times: 64 Temperature: room temperature Chemical shift reference material: Dimethyl sulfoxide

[0054] A more specific method for calculating the amount of FG at the main chain terminus of the aromatic polysulfone in this embodiment is as follows (Calculation Examples 1-3).

[0055] • Example 1 of calculating FG amount at the main chain terminal In this embodiment, the main chain of the aromatic polysulfone is composed of repeating units represented by the following formula (mc-1), and the end of the main chain has the structure represented by the following formula (e-1). In this case, the amount of FG per 100 repeating units represented by the following formula (mc-1) is calculated by the calculation method shown below. In the following formula, Xp is the peak area attributed to the hydrogen atom (Hx) in formula (mc-1), and Yp is the peak area attributed to the hydrogen atom (Hy) in formula (e-1).

[0056] Number of units n01 = Xp / 4 FG count = Yp / 2 FG amount=(Yp / 2) / (Xp / 4)×100 =Yp / Xp × 200

[0057] [ka]

[0058] [ka]

[0059] • Example 2 of calculating the amount of FG at the end of the main chain In this embodiment, the main chain of the aromatic polysulfone is composed of repeating units represented by the following formulas (mc-1) and (mc-2), and the end of the main chain has the structure represented by the following formula (e-1). In this case, the amount of FG per 100 units of the repeating units represented by the following formulas (mc-1) and (mc-2) is calculated by the following calculation method. In the following formulas, Xp is the peak area attributed to the hydrogen atom (Hx) in formula (mc-1), Zp is the peak area attributed to the hydrogen atom (Hz) in formula (mc-2), and Yp is the peak area attributed to the hydrogen atom (Hy) in formula (e-1).

[0060] Number of units n02 + n03 = Xp / 4 + Zp / 4 FG count = Yp / 2 FG amount=(Yp / 2) / (Xp / 4+Zp / 4)×100 =Yp / (Xp+Zp)×200

[0061] [ka]

[0062] [ka]

[0063] • Example 3 of calculating the amount of FG at the end of the main chain In this embodiment, the main chain of the aromatic polysulfone is composed of repeating units represented by the following formula (mc-3), and the end of the main chain has the structure represented by the following formula (e-1). In this case, the amount of FG per 100 repeating units represented by the following formula (mc-3) is calculated by the following calculation method. In the following formula, CH3p is the peak area attributed to the methyl group in formula (mc-3), and Yp is the peak area attributed to the hydrogen atom (Hy) in formula (e-1).

[0064] Number of units n04 = CH3p / 24 FG count = Yp / 2 FG amount=(Yp / 2) / (CH3p / 24)×100 =Yp / CH3p × 1200

[0065] [ka]

[0066] [ka]

[0067] For example, if the aromatic polysulfone of this embodiment is the aromatic polysulfone S1 described above, then the aromatic polysulfone of this embodiment is 1 This is an aromatic polysulfone in which the amount of Ra in the above formula (Se-1-1), calculated from the peak area ratio of 1H-NMR, is 0.35 to 40 per 100 repeating units of aromatic polysulfone S1. "100 repeating units of aromatic polysulfone S1" means 100 repeating units represented by formula (S-1-1) when X in formula (S-1-1) is a single bond. Furthermore, when X in formula (S-1-1) is a group derived from bisphenol or biphenol, it means a total of 100 repeating units, including the repeating units represented by formula (S-1-1) when X in formula (S-1-1) is a single bond, as well as the repeating units consisting of the group derived from bisphenol or biphenol.

[0068] In the above formula (Se-1-1), Ra is preferably a group represented by any of the above general formulas (Ra-1) to (Ra-4).

[0069] The aromatic polysulfone in this embodiment may be a single aromatic polysulfone or a mixture of two or more aromatic resins. In the case of a mixed resin of two or more types, the aromatic polysulfone of this embodiment may be a mixed resin of two or more aromatic polysulfones having FG at the main chain terminus, or it may be a mixed resin of an aromatic polysulfone having FG at the main chain terminus (aromatic polysulfone P1) and an aromatic polysulfone not having FG at the main chain terminus (aromatic polysulfone P0). In this case, in the mixed resin, 1 The amount of FG at the main chain terminus, calculated from the peak area ratio of 1H-NMR, should be 0.35 to 40 per 100 repeating units forming the main chain of the aromatic polysulfone.

[0070] The amount of FG at the main chain terminus of the aromatic polysulfone of this embodiment can be controlled by appropriately adjusting, for example, the amount of FG-containing compound added in the method for producing the aromatic polysulfone of this embodiment described later; the amount of base added in the method for producing the aromatic polysulfone of this embodiment described later; the mixing ratio of aromatic polysulfone P1 and aromatic polysulfone P0; and the degree of polymerization of the aromatic polysulfone.

[0071] In this embodiment, the aromatic polysulfone is preferably a mixed resin of aromatic polysulfone P1 and aromatic polysulfone P0, from the viewpoint of further improving the membrane properties (especially the water permeability) of the separation membrane formed from the aromatic polysulfone.

[0072] In other words, the aromatic polysulfone of this embodiment is a mixed resin of aromatic polysulfone P1 and aromatic polysulfone P0, 1 It is preferable that the aromatic polysulfone P1 and P0 have an amount of FG at the main chain terminals, calculated from the peak area ratio of 1H-NMR, of 0.35 to 40 per 100 repeating units forming the main chain.

[0073] Furthermore, the aromatic polysulfone of this embodiment includes an aromatic polysulfone having a repeating unit represented by the above general formula (S-1-1) and a terminal unit represented by the above general formula (Se-1-1), A mixed resin having repeating units represented by the above general formula (S-1-1) and an aromatic polysulfone that does not have FG at the end of the main chain (for example, an aromatic polysulfone having halogen atoms at the end of the main chain), 1 It is more preferable that the aromatic polysulfone is such that the amount of Ra in the above formula (Se-1-1), calculated from the peak area ratio of the 1H-NMR, is 0.35 to 40 per 100 repeating units represented by the above general formula (S-1-1).

[0074] The number-average molecular weight of the aromatic polysulfone in this embodiment is preferably 1,000 to 150,000, more preferably 8,000 to 130,000, and even more preferably 10,000 to 70,000. The number-average molecular weight (Mn) can be determined by gel permeation chromatography (GPC) analysis and represents the value calculated on a standard polystyrene basis, using a calibration curve obtained by measuring the molecular weight of standard polystyrene.

[0075] The aromatic polysulfone of this embodiment has a specific amount of FG at the main chain terminus, making it possible to form a separation membrane with high water permeability and high mechanical strength from the aromatic polysulfone. This is presumed to be because the placement of FG on the surface of the separation membrane increases its hydrophilicity, thereby improving water permeability, and because having FG only at the main chain terminus allows for the maintenance of a robust structure without weakening the interactions between the aromatic rings of the aromatic polysulfone. Furthermore, the amount of FG at the main chain terminal of the aromatic polysulfone in this embodiment is 0.5 By setting the temperature to ~40, the separation membrane formed from the aromatic polysulfone exhibits improved fouling resistance in addition to the effects described above. Therefore, the aromatic polysulfone of this embodiment is useful as a material for forming separation membranes.

[0076] (Resin composition) The resin composition of this embodiment contains the aromatic polysulfone described above. In this embodiment, a resin composition containing the above-mentioned aromatic polysulfone and filler is preferred.

[0077] <Filler> Examples of fillers include fibrous fillers, plate-shaped fillers, spherical fillers, powder-shaped fillers, and irregularly shaped fillers.

[0078] Examples of fibrous fillers include glass fibers, PAN-based carbon fibers, pitch-based carbon fibers, silica-alumina fibers, silica fibers, alumina fibers, other ceramic fibers, liquid crystal polymer (LCP) fibers, aramid fibers, and polyethylene fibers. Whiskers such as wollastonite and potassium titanate fibers are also used.

[0079] Examples of plate-shaped fillers include talc, mica, graphite, and wollastonite. The plate-shaped filler may be surface-treated or untreated. Examples of mica include natural mica such as muscovite, phlogopite, fluorphlogopite, and tetrasilicate mica, as well as synthetic mica that is artificially produced.

[0080] Examples of spherical fillers include glass beads and glass balloons.

[0081] Examples of powdered fillers include calcium carbonate, dolomite, barium clay sulfate, titanium dioxide, carbon black, conductive carbon, and fine silica.

[0082] Examples of irregularly shaped fillers include glass flakes and irregularly shaped cross-section glass fibers.

[0083] The filler content in the resin composition of this embodiment is preferably 0 to 250 parts by mass, more preferably 0 to 70 parts by mass, even more preferably 0 to 50 parts by mass, and particularly preferably 0 to 25 parts by mass, per 100 parts by mass of aromatic polysulfone.

[0084] <Optional ingredients> The resin composition of this embodiment may contain optional components other than the aromatic polysulfone and filler described above. Optional components include resins other than the aromatic polysulfone described above, organic solvents, colorants, lubricants, various surfactants, antioxidants, heat stabilizers, other stabilizers, UV absorbers, antistatic agents, and the like.

[0085] <<Resins other than aromatic polysulfone>> Examples of resins other than aromatic polysulfones include polyamides, polyesters, polyphenylene sulfides, polycarbonates, polyphenylene ethers, aromatic polyketones, polyetherimides, phenolic resins, epoxy resins, polyimide resins, and their modified products.

[0086] Organic solvents Examples of organic solvents include sulfoxides such as dimethyl sulfoxide; amides such as dimethylformamide, dimethylacetamide, and N-methyl-2-pyrrolidone; sulfones such as sulfolane (1,1-dioxotilane), dimethyl sulfone, diethyl sulfone, diisopropyl sulfone, and diphenyl sulfone; and 1,3-dimethyl-2-imidazolidinone and 1,3-diethyl-2-imidazolidinone.

[0087] The resin composition of this embodiment contains the above-mentioned aromatic polysulfone and is therefore useful as a material for forming separation membranes.

[0088] (Method for producing aromatic polysulfone) A method for producing aromatic polysulfone includes the step of reacting an aromatic polysulfone precursor having a halogen atom at the main chain terminus with a compound having FG to produce an aromatic polysulfone having FG at the main chain terminus.

[0089] One embodiment of a method for producing aromatic polysulfones includes the step (i) of preparing an aromatic polysulfone precursor having halogen atoms at the ends of the main chain, The process includes (ii) reacting an aromatic polysulfone precursor having a halogen atom at the main chain terminus with a compound having FG to produce an aromatic polysulfone having FG at the main chain terminus.

[0090] Process (i): The aromatic polysulfone precursor may be synthesized by the method described later, or it may be a commercially available product. Examples of commercially available aromatic polysulfone precursors include Sumika Excel® PES 3600P, 4800P, and 5900P (all are polyethersulfones, all manufactured by Sumitomo Chemical Co., Ltd.).

[0091] The number-average molecular weight of the aromatic polysulfone precursor is preferably 1,000 to 150,000, more preferably 8,000 to 130,000, and even more preferably 10,000 to 70,000. The number-average molecular weight (Mn) can be determined by gel permeation chromatography (GPC) analysis and represents the value calculated on a standard polystyrene basis, using a calibration curve obtained by measuring the molecular weight of standard polystyrene.

[0092] <Method for producing aromatic polysulfone precursors> The aromatic polysulfone precursor in this embodiment can be produced by using dihalogeno-aromatic sulfone compounds, dihydroxy aromatic compounds, etc., as monomers and carrying out a polycondensation reaction of these monomers in an organic solvent in the presence of a base.

[0093] Monomers Dihalogeno-aromatic sulfone compounds are compounds that have an aromatic ring, a sulfonyl group, and two halogen atoms bonded to the aromatic ring in one molecule. Dihydroxyaromatic compounds are compounds that have an aromatic ring and two hydroxyl groups bonded to the aromatic ring in one molecule. Dihalogenoaromatic sulfone compounds and dihydroxyaromatic compounds correspond to the repeating units that constitute aromatic polysulfone precursors.

[0094] When the aromatic polysulfone precursor in the present embodiment has a repeating unit containing the structure represented by the above formula (S-1), as the dihalogenoaromatic sulfone compound, a compound represented by the following formula (mx-1) is used, and as the dihydroxyaromatic compound, a compound represented by the following formula (my-1) is used, whereby an aromatic polysulfone precursor having a repeating unit containing the structure represented by the above formula (S-1) can be produced. X 1 -ph 1 -SO2-ph 2 -X 2 ···(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. In formula (my-1), ph 1 and ph 2 are each independently a phenylene group which may have a substituent.]

[0095] In formulas (mx-1) and (my-1), ph 1 and ph 2 are the same as ph 1 and ph 2 in the above formula (S-1) respectively.

[0096] 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 preferable.

[0097] Examples of the compound represented by formula (mx-1) include bis(4-chlorophenyl)sulfone, 4-chlorophenyl-3’,4’-dichlorophenylsulfone, and the like.

[0098] Examples of the compound represented by the formula (my-1) include bis(4-hydroxyphenyl)sulfone, bis(4-hydroxy-3,5-dimethylphenyl)sulfone, and bis(4-hydroxy-3-phenylphenyl)sulfone.

[0099] When the aromatic polysulfone precursor in the present embodiment has a repeating unit containing the structure represented by the above formula (S-1) and the structure represented by the above formula (S-2), as the dihalogenoaromatic sulfone compound, the compound represented by the above formula (mx-1) is used, and as the aromatic dihydroxy compound, the compound represented by the following formula (my-2) is used, whereby an aromatic polysulfone precursor having a repeating unit containing the structure represented by the above formula (S-1) and the structure represented by the above formula (S-2) can be produced. HO-ph 3 -R-ph 4 -OH ···(my-2) [In the 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.]

[0100] In the 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.

[0101] Examples of the compound represented by the 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.

[0102] In this embodiment, if the aromatic polysulfone precursor has repeating units including the structure represented by formula (S-1) and the structure represented by formula (S-3) described above, an aromatic polysulfone precursor having repeating units including the structure represented by formula (S-1) and the structure represented by formula (S-3) described above can be produced by using the compound represented by formula (mx-1) as the dihalogeno-aromatic sulfone compound and the compound represented by formula (my-3) described below as the dihydroxy-aromatic compound.

[0103] HO-(ph 5 ) n -OH ···(my-3) [In formula (my-3), ph 5 is a phenylene group which may have substituents. n is an integer from 1 to 3. If n is 2 or greater, there are multiple ph 5 They may be the same or different from each other.

[0104] In formula (my-3), ph 5 and n are the ph in formula (S-3) described above. 5 These are identical to and n, respectively.

[0105] Compounds 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.

[0106] In this embodiment, depending on the type of aromatic polysulfone to be used, one dihalogeno-aromatic sulfone compound and one dihydroxy aromatic compound may be used alone, or two or more may be used in combination.

[0107] Bases, organic solvents The polycondensation of a dihalogeno aromatic sulfone compound and a dihydroxy aromatic compound is preferably carried out using an alkali metal salt of carbonic acid as a base. Further, the polycondensation is preferably carried out in an organic solvent. More preferably, the polycondensation is carried out using an alkali metal salt of carbonic acid as a base and in an organic solvent.

[0108] The alkali metal salt of carbonic acid may be an alkali carbonate (alkali metal carbonate), an alkali bicarbonate (alkali metal hydrogen carbonate), or a mixture thereof. Examples of the alkali carbonate include sodium carbonate and potassium carbonate. Examples of the alkali bicarbonate include sodium bicarbonate (sodium hydrogen carbonate) and potassium bicarbonate (potassium hydrogen carbonate).

[0109] 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.

[0110] Examples of such organic solvents include sulfoxides such as dimethyl sulfoxide; amides such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone; sulfones such as sulfolane (1,1-dioxothiirane), dimethyl sulfone, diethyl sulfone, diisopropyl sulfone, and diphenyl sulfone; and 1,3-dimethyl-2-imidazolidinone, 1,3-diethyl-2-imidazolidinone, and the like.

[0111] The organic solvent may be used alone or in combination of two or more.

[0112] <B The reaction temperature of the polycondensation is preferably 180°C or higher and 400°C or lower, and the reaction time is preferably 4 to 10 hours.

[0113] Step (ii) <Compound having FG> The compound having FG (hereinafter also referred to as "end capping agent") is not particularly limited as long as it is a compound that can substitute FG for the halogen atom at the end of the main chain of the aromatic polysulfone precursor. Examples of end capping agents include 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, and (3-hydroxyphenyl)phosphonic acid and its alkali metal salts.

[0114] Step (ii) may be carried out in an organic solvent in the presence of a base, and the organic solvent and base are the same as those described in the above-mentioned method for producing aromatic polysulfone precursors.

[0115] The reaction temperature for reacting the aromatic polysulfone precursor with the end capping agent is preferably 100 to 300°C or lower, and the reaction time is preferably 4 to 15 hours.

[0116] The amount of end capping agent used in step (ii) is preferably 0.1 to 50 parts by mass, and more preferably 0.6 to 25 parts by mass, per 100 parts by mass of aromatic polysulfone precursor.

[0117] The amount of base used in step (ii) is preferably 0.3 to 30 parts by mass, and more preferably 0.4 to 10 parts by mass, per 100 parts by mass of aromatic polysulfone precursor. [Examples]

[0118] The present invention will be described in more detail below with reference to specific examples. However, the present invention is not limited in any way to the examples shown below.

[0119] <Production of Aromatic Polysulfone Having FG at the Main Chain End> [Example 1] In a polymerization tank equipped with a stirrer, a nitrogen introduction tube, a thermometer, and a condenser with a receiver at the tip, 1.7 g of sodium 4-hydroxybenzenesulfonate (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.92 g of potassium carbonate, and 150 g of N-methyl-2-pyrrolidone (hereinafter abbreviated as NMP) were mixed. After heating to 100 °C, 100 g of polyethersulfone (Sumikaexcel PES 3600P, manufactured by Sumitomo Chemical Co., Ltd.) was added. After the polyethersulfone was dissolved, it was heated at 200 °C and reacted for 14 hours. Next, the obtained reaction mixture solution was diluted with NMP and cooled to room temperature to precipitate unreacted potassium carbonate and by-produced potassium chloride. The above solution was dropped into water to precipitate an aromatic polysulfone, and unnecessary NMP was removed by filtration to obtain a precipitate. The obtained precipitate was carefully washed repeatedly with methanol and water and dried by heating at 150 °C to obtain the aromatic polysulfone of Example 1 having FG at the main chain end. FG in this example is a salt-type sulfonic acid group (hereinafter referred to as FGS) containing a sodium sulfonate group and a potassium sulfonate group.

[0120] [Example 2] An aromatic polysulfone of Example 2 having FGS at the main chain end was obtained in the same manner as in Example 1 above, except that the blending amount of sodium 4-hydroxybenzenesulfonate was changed to 0.92 g, the blending amount of potassium carbonate was changed to 0.54 g, and polyethersulfone with different molecular weights (Sumikaexcel PES 4800P, manufactured by Sumitomo Chemical Co., Ltd.) was used.

[0121] [Example 3] An aromatic polysulfone of Example 3 having FGS at the main chain end was obtained in the same manner as in Example 1 above, except that the blending amount of sodium 4-hydroxybenzenesulfonate was changed to 0.54 g, the blending amount of potassium carbonate was changed to 0.46 g, and polyethersulfone with different molecular weights (Sumikaexcel PES 5900P, manufactured by Sumitomo Chemical Co., Ltd.) was used.

[0122] [Example 4] Except for changing the amount of sodium 4-hydroxybenzenesulfonate to 0.27 g, changing the amount of potassium carbonate to 0.46 g, and using a polyethersulfone with a different molecular weight (Sumitomo Chemical Co., Ltd., Sumika Excel PES 5900P), an aromatic polysulfone of Example 4 having FGS at the main chain terminus was obtained by the same method as in Example 1 above.

[0123] [Example 5] The aromatic polysulfone of Example 5 having FGS at the main chain terminus was obtained in the same manner as in Example 1, except that the amount of sodium 4-hydroxybenzenesulfonate was changed to 8.1 g, the amount of potassium carbonate was changed to 3.6 g, and 5.5 g of 4,4'-dichlorodiphenylsulfone was mixed in.

[0124] [Example 6] The aromatic polysulfone of Example 6 having FGS at the main chain terminus was obtained in the same manner as in Example 1, except that the amount of sodium 4-hydroxybenzenesulfonate was changed to 5.4 g, the amount of potassium carbonate was changed to 2.4 g, and 3.0 g of 4,4'-dichlorodiphenylsulfone was mixed in.

[0125] [Example 7] Ten parts by mass of the aromatic polysulfone from Example 5 and 90 parts by mass of polyethersulfone (Sumitomo Chemical Co., Ltd., Sumika Excel PES 5900P) aromatic polysulfone were mixed to obtain the aromatic polysulfone from Example 7.

[0126] [Example 8] 30 parts by mass of the aromatic polysulfone from Example 6 and 70 parts by mass of polyethersulfone (Sumitomo Chemical Co., Ltd., Sumika Excel PES 5900P) aromatic polysulfone were mixed to obtain the aromatic polysulfone from Example 8.

[0127] [Example 9] 50 parts by mass of the aromatic polysulfone of Example 6 and 50 parts by mass of a polyethersulfone (Sumikaexcel PES 5900P, manufactured by Sumitomo Chemical Co., Ltd.) were mixed to obtain the aromatic polysulfone of Example 9.

[0128] [Example 10] 50 parts by mass of the aromatic polysulfone of Example 5 and 50 parts by mass of a polyethersulfone (Sumikaexcel PES 5900P, manufactured by Sumitomo Chemical Co., Ltd.) were mixed to obtain the aromatic polysulfone of Example 10. [Comparative Example 1] An aromatic polysulfone of Comparative Example 1 in which a part of specific repeating units was randomly sulfonated was obtained in the same manner as in Comparative Example 1 of JP-A-2013-215640.

[0129] [Comparative Example 2] 20 parts by mass of the aromatic polysulfone of Comparative Example 1 and 80 parts by mass of a polyethersulfone (Sumikaexcel PES 5900P, manufactured by Sumitomo Chemical Co., Ltd.) were mixed to obtain the aromatic polysulfone of Comparative Example 2.

[0130] [Comparative Example 3] As the aromatic polysulfone of Comparative Example 3, a polyethersulfone (Sumikaexcel PES 5900P, manufactured by Sumitomo Chemical Co., Ltd.) was prepared.

[0131] <Measurement of FG amount> [Solution 1 [Measurement of 1H-NMR] A solution for calculating the amount of FG per 100 units of the repeating unit forming the main chain of the aromatic polysulfone of each example <## 1 For 1H-NMR measurement, a sample in which the aromatic polysulfone of each example was dissolved in deuterated dimethyl sulfoxide so that the concentration of the aromatic polysulfone of each example was 80 mg / mL was used. The measurement conditions were as follows. Measuring device: ECZ400S (manufactured by JEOL Ltd.) Static magnetic field strength: 9.4 tesla (resonance frequency: 400 MHz ( 1 1H)) Spinning: 15 Hz Repeat time: 7.2s Total number of times: 64 Temperature: room temperature Chemical shift reference material: Dimethyl sulfoxide

[0132] [Calculation of FG amount at the main chain end per 100 repeating units forming the main chain of aromatic polysulfone] The amount of FG at the end of the aromatic polysulfone main chain in each example is per 100 repeating units forming the main chain of the aromatic polysulfone (A 01 ) was calculated by NMR measurement. Specifically, 1 ¹H NMR measurement revealed the (-ph) of the main chain of aromatic polysulfone. 1 -SO2-ph 2 -O-) where ph is attached to S 1 The two hydrogen atoms bonded to the two carbon atoms adjacent to the carbon atom, and the ph bonded to S 2 The peak area (Xp) is attributed to the two hydrogen atoms bonded to the two carbon atoms adjacent to the carbon atom (a total of four hydrogen atoms). 01 ) and the peak area (Yp) attributed to the two hydrogen atoms bonded to the two carbon atoms adjacent to the carbon atom to which FG is bonded in the aromatic ring at the end of the main chain of the aromatic polysulfone. 01 The calculation was performed using the following formula (a1). A 01 =(Yp 01 / 2) / (Xp 01 / 4) × 100 =Yp 01 / Xp 01 ×200···(a1) XP 01 For this purpose, an integral value of 7.25 to 7.27 ppm was adopted. Also, Yp 01 For this analysis, we adopted an integral value of 7.02 to 7.04 ppm.

[0133] [Calculation of FG amount in the main chain per 100 repeating units forming the main chain of aromatic polysulfone] The amount of FG in the main chain of each example of aromatic polysulfone per 100 repeating units forming the main chain of each example (A 02 The following formula was used to calculate it. in particular, 1 ¹H NMR measurement revealed the (-ph) of the main chain of aromatic polysulfone. 1 -SO2-ph 2 -O-) where ph is attached to S 1 The two hydrogen atoms bonded to the two carbon atoms adjacent to the carbon atom, and the ph bonded to S 2 The peak area (Xp) is attributed to the two hydrogen atoms bonded to the two carbon atoms adjacent to the carbon atom (a total of four hydrogen atoms). 02 ) and the pH of the FG of the main chain of the aromatic polysulfone is bonded. 1 or ph 2 The peak area (Cp) is attributed to one hydrogen atom bonded to one carbon atom adjacent to the carbon atom. 02 Using ), the calculation was performed based on the following formula (a2). A 02 =Cp 02 / {(Xp 02 / 4)+Cp 02} × 100···(a2) XP 02 For this purpose, an integral value of 7.9 to 8.05 ppm was adopted. Also, Cp 02 For this analysis, we adopted an integral value of 8.2 to 8.35 ppm.

[0134] Table 1 shows the amount of FG at the main chain ends of the aromatic polysulfones in Examples 1 to 10 and the amount of FG in the main chain of the aromatic polysulfones in Comparative Examples 1 and 2. In Table 1, a "-" next to the FG amount indicates that the value was below the detection limit. The amount of sodium 4-hydroxybenzenesulfonate used is also listed in Table 1.

[0135] [Table 1]

[0136] <Fabrication of porous membranes> In a heated container, 18% by mass of either the aromatic polysulfones from Examples 1-4, 7-9, or Comparative Examples 2 and 3 was mixed with 82% by mass of NMP, and the mixture was stirred at 80°C for 2 hours to obtain a pale yellow solution. These solutions were then applied to one surface of a 3 mm thick glass plate using a film applicator, and then immersed in water to form porous films with a thickness of 140-170 μm, each consisting of the aromatic polysulfones from Examples 1-4, 7-9, or Comparative Examples 2 and 3. The porous material from each example was peeled off the glass plate, washed multiple times with water, and then stored in water until the start of measurement.

[0137] [Measurement of water permeability] A pressure cell with a diameter of 47 mm was used, and each porous membrane was cut into a circular shape so that it could be fitted into the pressure cell, thereby creating test membranes for each example. Each test membrane was fitted into the pressure cell, and pure water was filtered through each test membrane at 23°C and a pressure of 0.2 bar (20 kPa). The amount of pure water that permeated through each test membrane was measured between 9 minutes 30 seconds and 10 minutes (30 seconds) from the start of filtration, and the water permeability rate (L / m³) was determined. 2 / h / 10 5 We calculated Pa. The results are shown in Table 2.

[0138] [Evaluation of fouling resistance] Using the same method as described above for [Measurement of Water Permeability], the amount of pure water that permeated each test membrane was measured between 9 minutes 30 seconds and 10 minutes after the start of filtration (30 seconds), and the water permeability (J0) was determined. Next, using each test membrane, a bovine serum albumin aqueous solution (100 ppm) was filtered at the same pressure for 1 hour. After that, each test membrane was turned inside out, and pure water was filtered for 2 minutes at 23°C and a pressure of 0.1 bar (10 kPa) to wash the membrane. Again, each test membrane was turned inside out, and pure water was filtered at 23°C and a pressure of 0.2 bar (20 kPa), and the amount of pure water that permeated each test membrane was measured between 9 minutes 30 seconds and 10 minutes after the start of filtration (30 seconds), and the water permeability (J) was determined. The recovery rate (%) of the water permeability of each test membrane was calculated from the obtained water permeability (J0) and water permeability (J) using the following formula. The results are shown in Table 2. A higher rate of recovery in water permeability indicates greater resistance to fouling. Permeability recovery rate (%) = (J / J0) × 100 J0: Permeability of bovine serum albumin before filtration (L / m 2 / h / 10 5 Pa) J: Permeability of bovine serum albumin after filtration (L / m 2 / h / 10 5 Pa)

[0139] [Table 2]

[0140] As shown in Table 2, the porous membrane formed using the aromatic polysulfone in the example had a higher water permeability and superior water permeability compared to the porous membrane formed using the aromatic polysulfone in the comparative example.

[0141] Among the aromatic polysulfones in the examples, porous membranes formed using the aromatic polysulfones of Examples 1, 2, and 7-9, which have a high amount of FG at the main chain terminals, were found to have a higher recovery rate of water permeability and superior fouling resistance. Furthermore, it was confirmed that porous membranes formed using the aromatic polysulfones of Examples 7-9, which are mixed resins of aromatic polysulfones having FG at the main chain end and aromatic polysulfones not having FG at the main chain end, exhibit superior water permeability compared to the other examples.

[0142] <Cast film production> In a heated container, 18% by mass of either the aromatic polysulfones of Examples 1-4, 7-9, or Comparative Examples 2 and 3 was mixed with 82% by mass of NMP, and the mixture was stirred at 80°C for 2 hours to obtain a pale yellow solution. These solutions were applied to one surface of a 3 mm thick glass plate using a film applicator, and then dried at 60°C using a high-temperature hot air dryer to form the respective coating films. These coating films were heat-treated at 250°C while flowing nitrogen to form 30 μm thick films on the glass plate. These films were peeled off the glass plate to obtain films made of the aromatic polysulfones of Examples 1-4, 7-9, or Comparative Examples 2 and 3.

[0143] [Measurement of film tensile strength] The tensile strength of each example film was measured in accordance with JIS K7127. Specifically, first, each example of film with a thickness of 30 μm was punched out to obtain dumbbell-shaped test specimens of type 3 as specified in JIS K6251. Next, using each example of test specimen, the tensile strength (the value obtained by dividing the tensile load by the cross-sectional area of ​​the test specimen) at which the test specimen broke (fractured) was measured using an autograph with a gripping distance of 50 mm and a tensile speed of 5 mm / min in an atmosphere of 23°C and 50% RH. The results are shown in Table 3.

[0144] [Table 3]

[0145] As shown in Table 3, the film formed using the aromatic polysulfone of the example was found to have higher tensile strength and superior mechanical strength compared to the film formed using the aromatic polysulfone of the comparative example.

[0146] While preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments. Additions, omissions, substitutions, and other modifications are possible without departing from the spirit of the invention. The present invention is not limited by the foregoing description, but only by the scope of the appended claims.

Claims

1. An aromatic polysulfone having one or more functional groups selected from the group consisting of acidic groups having a pKa less than or equal to the pKa of a carboxyl group and salts of said acidic groups at the end of the main chain, The acidic group having a pKa less than or equal to the pKa of the carboxyl group is one or more acidic groups selected from the group consisting of a carboxyl group (-COOH), a sulfonic acid group (-SO₂OH), a sulfinic acid group (-SO₂H), and a phosphate group (H₂PO₄-). The aromatic polysulfone is a mixed resin of an aromatic polysulfone having the functional group at the end of the main chain (aromatic polysulfone P1) and an aromatic polysulfone not having the functional group at the end of the main chain (aromatic polysulfone P0). １ An aromatic polysulfone in which the amount of the functional group, calculated from the peak area ratio of 1H-NMR, is 0.35 to 40 per 100 repeating units forming the main chain of the aromatic polysulfone P1 and aromatic polysulfone P0.

2. The aromatic polysulfone according to claim 1, having repeating units containing a structure represented by the following general formula (S-1) and terminal units represented by the following general formula (Se-1). -ph １ -SO ２ -ph ２ -O- ・・・(S-1) -ph １ -SO ２ -ph ２ -O-Ar-Ra ・・・(Se-1) [wherein, ph １ and ph ２ are each independently a phenylene group which may have a substituent. Ar is an aromatic hydrocarbon group which may have a substituent. Ra is one or more functional groups selected from the group consisting of an acidic group having a pKa not higher than the pKa of a carboxy group and salts of said acidic group.]

3. The aromatic polysulfone according to claim 1 or 2, wherein the amount of the functional group is 0.7 to 40 per 100 repeating units.

4. A resin composition comprising an aromatic polysulfone according to any one of claims 1 to 3 and a filler.

5. A method for producing aromatic polysulfone according to any one of claims 1 to 3, A method for producing an aromatic polysulfone, comprising the step of reacting an aromatic polysulfone precursor having a halogen atom at the main chain terminus with a compound having the functional group to produce an aromatic polysulfone having the functional group at the main chain terminus.

Images