Polyamic acid resin, polyimide resin, and resin composition including these

A polyimide resin which is an imidization compound of a polyamic acid resin which is a reaction product of an amino phenol compound (a) selected from a group consisting of 3,3′-diamino-4,4′-dihydroxydiphenylsulfone and 2,2-bis(3-amino-4-hydroxyphenyl) hexafluoropropane, at least one of an aliphatic diamino compound (b) comprising a dimer diamine, a tetrabasic acid dianhydride (c) comprising a compound of a following formula (6):

• wherein in formula (6) Y represents a bivalent connection group represented by-C(CF3)2-,-SO2-,-CO-or following formula (2):
• an oxygen atom, or a direct bond, and an aromatic diamino compound (d),
• wherein the polyamic acid resin has an amino group at both ends thereof,
• wherein a phenolic hydroxy group equivalent of the polyimide resin is in the range from 1,500 to 25,000 g/eq., and
• wherein an amount of the aliphatic diamino compound (b) is within a range from 10 to 50% of mass of the polyimide resin.