Benzoxazine resin composition, and fiber-reinforced composite material

A benzoxazine resin composition comprising:

• (a) a compound having in its molecule a benzoxazine ring represented by formula (1):
• wherein R1 stands for a chain alkyl group having 1 to 12 carbon atoms, a cyclic alkyl group having 3 to 8 carbon atoms, a phenyl group, or a phenyl group substituted with a chain alkyl group having 1 to 12 carbon atoms or a halogen, and a hydrogen atom is bonded to at least one of the carbon atoms of the aromatic ring at ortho- or para-position with respect to the carbon atom to which the oxygen atom is bonded;
• (B) an epoxy resin;
• (C) a curing agent;
• (D) a toughness improver;
• and
• (E2) polyamide 12 powder particles having an average particle size of not smaller than 15 μm and not larger than 60 μm;
• wherein a content of said component (A) is 65 to 78 mass % and a content of said component (B) is 22 to 35 mass %, with a total of components (A) and (B) being 100 mass %;
• wherein, with respect to 100 parts by mass of the total of components (A) and (B), a content of said component (C) is 5 to 20 parts by mass, a content of said component (D) is 3 to 20 parts by mass, and a content of said component (E2) is not less than 5 parts by mass and less than 20 parts by mass, and
• wherein the component (D) is dissolved.