Method for producing aromatic polysulfone

A method for producing an aromatic polysulfone by a polycondensation reaction between an aromatic dihalogenosulfone compound and an aromatic dihydroxy compound, wherein:

• the polycondensation reaction is performed in the presence of at least one aromatic end-capping agent;
• and
• an amount, p mol, of the aromatic dihalogenosulfone compound, an amount, q mol, of the aromatic dihydroxy compound, and an amount, r mol, of the aromatic end-capping agent have a relationship satisfying formula (S2) below and formula S3 below:
• p>q (S2)
• 0.5≤r/(p−q)≤1.5 (S3)
• wherein the aromatic end-capping agent is represented by formula (8):
• Ar—Y (8)
• wherein Y represents —OH, —SH, or NH2 and Ar represents an aromatic group, and
• wherein the aromatic dihydroxy compound is at least one compound selected from the group consisting of compounds represented by the formulas (5) to (7),
• HO—Ph1—SO2—Ph2—OH (5)
• wherein Ph1 and Ph2 represents a phenylene group, and one or more hydrogen atoms of the phenylene group are each independently optionally substituted by an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 20 carbon atoms, or a halogen atom,
• HO—Ph3—R1—Ph4—OH (6)
• wherein Ph3 and Ph4 represents a phenylene group, and one or more hydrogen atoms of the phenylene group are each independently optionally substituted by an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 20 carbon atoms, or a halogen atom;
• and R1 is an alkylidene group having 1 to 5 carbon atoms, an oxygen atom or a sulfur atom,
• HO—(Ph5)n—OH (7)
• wherein Ph5 represents a phenylene group, and one or more hydrogen atoms of the phenylene group are each independently optionally substituted by an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 20 carbon atoms, or a halogen atom;
• and n is an integer of 1 to 3, with the proviso that, when n is 2 or more, a plurality of Ph5 is the same or different.