Fiber sizing agent composition, fiber sizing agent dispersion, fiber sizing agent solution, method for producing fiber bundles, composite intermediate and fiber-reinforced composite material

A fiber sizing agent composition comprising:

• a polyester resin (A);
• a reactive compound (B), and
• a resin (C) other than the polyester resin (A),
• wherein the polyester resin (A) is a polyester resin having an HLB of 4 to 18 and a viscosity at 30° C. of 10 to 1,000,000 Pa·s,
• the reactive compound (B) is a blocked isocyanate,
• a blocking agent for the blocked isocyanate is an amine,
• the resin (C) is at least one selected from the group consisting of polyester resins other than the polyester resin (A), epoxy resins, polyurethane resins, (meth)acrylic resins, unsaturated polyester resins, and polyamide resins,
• the weight ratio of the polyester resin (A) to the reactive compound (B) [(A)/(B)] in the fiber sizing agent composition is 99.9/0.1 to 10/90, and
• the weight ratio of the reactive compound (B) to the resin (C) [(B)/(C)] in the fiber sizing agent composition is ⅕ to 1/450.