Tow prepreg, composite material-reinforced pressure vessel, and method of producing composite material-reinforced pressure vessel

A method of producing a composite material-reinforced pressure vessel, the method comprising:

• preparing a matrix resin composition which contains a component (A), a component (B), a component (C), and a component (D), wherein the component (A) is an epoxy resin, the component (B) is dicyandiamide, the component (C) is a curing accelerator, and the component (D) is a core-shell rubber particle and a content of the component (D) with respect to 100 parts by mass of the component (A) is from 22.7 to 70 parts by mass and has a viscosity of from 3 Pa·s to 80 Pa·s at 30° C. and a minimum viscosity of from 0.04 Pa·s to 1 Pa·s to be obtained when a viscosity of the matrix resin composition is measured by raising a temperature from room temperature to 130° C. at a rate of temperature rise of 2.0° C./min;
• impregnating a reinforcing fiber bundle with the matrix resin composition to fabricate a resin-impregnated reinforcing fiber bundle;
• winding the resin-impregnated reinforcing fiber bundle onto a rotating metal liner or resin liner to fabricate a pressure vessel intermediate body;
• and
• heating the pressure vessel intermediate body to cure the matrix resin composition contained in the resin-impregnated reinforcing fiber bundle.