Polycarbonate copolymer, coating fluid using same, electrophotographic photoreceptor, and method for producing polycarbonate copolymer

A polycarbonate copolymer, comprising a structure formed of a repeating unit represented by formula (1),

• wherein:
• a molar copolymer composition represented by Ar1/(Ar1+Ar2+Ar3) is in a range of 47 mol % to 67 mol %;
• a reduced viscosity [ηsp/C] is in a range of 0.60 dl/g to 4.0 dl/g;
• a ratio of a hydroxyl group at all ends is 20 mol % or less;
• Ar2 and Ar3 each represent a divalent group having an aromatic group;
• Ar1 represents a group represented by the following formula (2):
• chain ends are terminated by a monovalent aromatic group or a monovalent fluorine-containing aliphatic group;
• n represents an average repeating number of an Ar1 block and is a numeral of 1.0 to 1.99;
• m represents an average repeating number of an Ar3 block and is a numeral of 1.0 to 4.0;
• and
• Ar2 and Ar3 are optionally the same or different, but Ar1 is not the same as Ar2 and Ar3;
• R1 and R2 each represent a halogen atom, a trifluoromethyl group, an alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted aryl group having 6 to 12 ring carbon atoms, an alkoxy group having 1 to 12 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 12 ring carbon atoms, or a substituted or unsubstituted arylalkyl group having 7 to 20 carbon atoms;
• p1 and p2 each represent an integer of 0 to 4;
• and
• when the aromatic ring is substituted by two or more of R1 or R2 (p1, p2>2), the two or more of R1 or R2 are optionally different groups.

A manufacturing method of a polycarbonate copolymer, the method comprising reacting a bischloroformate oligomer represented by formula (5) or a combination of formulae (5) and (6) with a divalent phenol monomer represented by formula (7) in the presence of an acid binding agent:

• wherein:
• when a mole number of the bischloroformate oligomer is represented by Mc (mol), a mole number of the divalent phenol monomer is represented by Mp (mol), a mole number of the acid binding agent is represented by Mo (mol), and a valence of the acid binding agent is represented by Y, an acid binding value X represented by the following formula is in a range of 1.1 to 1.3:
• X=Mo·Y/(2Mc−2Mp),
• Ar1 is a group represented by formula (2):
• Ar2 and Ar3 are a divalent group having an aromatic group;
• Ar2 and Ar3 are optionally the same or different, but Ar1 is not the same as Ar2 and Ar3;
• n′ is a numeral of 1.0 to 1.99;
• n″ is 0 or a numeral of 1.0 to 4.0;
• R1 and R2 each represent a halogen atom, a trifluoromethyl group, an alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted aryl group having 6 to 12 ring carbon atoms, an alkoxy group having 1 to 12 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 12 ring carbon atoms, or a substituted or unsubstituted arylalkyl group having 7 to 20 carbon atoms;
• p1 and p2 each represent an integer of 0 to 4;
• and
• when the aromatic ring is substituted by two or more of R1 or R2 (p 1, p2≧2), the two or more of R1 or R2 are optionally different groups.