Curable resin composition, resin composition, resin sheet formed by using said curable resin composition and resin composition, and cured materials thereof

A curable resin composition comprising (A) 100 parts by mass of polyfunctional epoxy component, (B) 25 to 200 parts by mass of polyfunctional cyanic acid ester compound having two or more cyanato groups and (C) 0.5 to 20 parts by mass of an imidazole compound as a curing agent, wherein said polyfunctional epoxy component (A) is comprised of (A1) a trifunctional epoxy compound having three glycidyl groups in a molecule and (A2) a tetrafunctional epoxy compound having four glycidyl groups in a molecule so that a ratio of (A1):(A2) is from 10:90 to 90:10 in terms of mass, wherein said trifunctional epoxy compound (A1) is an epoxy compound which has an aromatic hydrocarbon moiety having one or more aromatic rings which is unsubstituted or substituted by halogen atoms, wherein no methylene group are contained but may contain an ether bond between carbon-carbon atoms, and three glycidyloxy groups, or one glycidyloxy group and one diglycidylamino group are bonded to said aromatic ring(s);

• and said tetrafunctional epoxy compound (A2) is an epoxy compound which has an aromatic hydrocarbon moiety having one or more aromatic rings which are unsubstituted or substituted by a halogen atom, wherein no methylene group is contained but may contain an ether bond between carbon-carbon atoms, and at least one group selected from the glycidyloxy group and the diglycidyl amino group is bonded to said aromatic ring(s).