Curable composition and fiber reinforced composite material

A method for producing a fiber-reinforced resin molded article, the method comprising heat-curing a fiber-reinforced composite material;

• wherein the fiber-reinforced composite material comprises a curable composition and a reinforcing fiber as essential components;
• wherein the curable composition is a curable composition comprising a urethane-modified epoxy resin (A) as an essential component of a main material, and an acid anhydride (B) as an essential component of a curing agent, wherein the urethane-modified epoxy resin (A) is a reaction product of a polyisocyanate compound (a1), a polyester polyol (a2), and a hydroxyl group-containing aromatic bifunctional epoxy resin (a3) as essential reaction raw, and wherein the polyisocyanate compound (a1) and the hydroxyl group-containing epoxy resin (a3) are reacted with each other to obtain an isocyanate group-containing intermediate, and then the polyester polyol (a2) and an optional additional polyol compound used are reacted with the intermediate;
• wherein the epoxy equivalent of the urethane-modified epoxy resin (A) is 150 to 300 g/equivalent;
• and
• wherein the polyester polyol (a2) is a polyester diol having a number average molecular weight (Mn) of 500 to 4,000.