Epoxy resin composition, prepreg, carbon fiber-reinforced composite material, and manufacturing methods therefor

An epoxy resin composition, comprising at least:

• component [A];
• 3 to 20 parts by mass of component [B] with respect to 100 parts by mass of the component [A];
• 6 to 20 parts by mass of component [C] with respect to 100 parts by mass of the component [A];
• and
• 5 to 35 parts by mass of component [D] with respect to 100 parts by mass of the component [A],
• wherein a viscosity at 50° C. of the epoxy resin composition is 50 to 1000 Pa·s,
• the mixture of component [A] and component [B] is a mixture that initiates thickening at temperature (T1) and completes thickening at temperature (T2) when temperature increases at 2° C./min, the temperature (T1) being 85 to 110° C., and the temperature (T1) and the temperature (T2) satisfying a relationship of the following formula (1)
• 5° C.≤(T2−T1)≤20° C. formula (1), and
• the mixture of component [A] and component [C] is a mixture that initiates curing at temperature (T3) when temperature increases at 2° C./min, and the temperature (T1) and the temperature (T3) satisfying a relationship of the following formula (2)
• 5° C.≤(T3−T1)≤80° C. formula (2), and
• wherein
• component [A] is epoxy resin containing 40 to 85 mass % of a glycidylamine type epoxy resin,
• component [B] is thickening particles which is a polymer including one or more polymerization units selected from the group consisting of a methacrylic acid ester-based compound, an acrylic acid ester-based compound, and a vinyl-based compound, and wherein the thickening particles are dispersed in and swell in the epoxy resin [A] by heating,
• component [C] is curing agent, and
• component [D] is thermoplastic resin in which at least a part is dissolved in the component [A].