Prepreg and fiber reinforced composite material

A prepreg which comprises:

• a resin layer comprising components [B] to [D] and optionally [E], wherein the resin layer is laminated on both sides of a sheet base material layer that comprises [A] a carbon fiber,
• wherein optional component [E] comprises particles
• having a number average primary particle size of 5 to 50 μm,
• having a content ratio (% by mass) of thermoplastic resin and thermosetting resin of 95:5 to 70:30, and
• generating a crack that has a size of 20 μm or less when the particle is immersed in methyl ethyl ketone and boiled and refluxed for 24 hours wherein the number of generated cracks is 5 or less,
• [B] an epoxy resin having two or more glycidyl groups in one molecule,
• [C] an aromatic amine compound, and
• [D] a thermoplastic resin having a polyarylether skeleton, and
• the prepreg satisfies the following conditions (I) to (VI) in the resin layer:
• Condition (I):
• 80% by mass or more of the component [B] is an epoxy resin having a viscosity at 25° C. of 2.0×104 mPa·s or more,
• Condition (II):
• a ratio of the number of active hydrogens in the component [C] to the number of epoxy groups in the component [B] is 0.7 to 1.3 as a molar ratio,
• Condition (III):
• the prepreg comprises 15 to 25 parts by mass of the component [D] with respect to 100 parts by mass of the component [B],
• Condition (IV):
• the prepreg comprises 50 to 80 parts by mass of the component [E] with respect to 100 parts by mass of the component [B],
• Condition (V):
• a minimum value of loss tangent tans of a resin composition comprising the layer in a temperature range of 12 to 25° C. is 1.0 or less,
• Condition (VI):
• a thickness of the resin layer is 7% or more of an average thickness of the prepreg,
• and 85% by mass or more of the particles of component [E] is present in a region from both surfaces of the prepreg to 9% of the average thickness.