Thermosetting prepreg and method for manufacturing same

A method for producing a thermosetting prepreg, comprising:

• (a) providing a thermosetting prepreg precursor sheet, wherein the precursor sheet has a fiber sheet and first and second thermosetting resin compositions, each of these compositions being impregnated in the fiber sheet and containing a thermosetting resin and a curing agent, and wherein, in the cross section perpendicular to the plane direction of the fiber sheet, the first thermosetting resin composition is impregnated in a first outer region in the thickness direction of the fiber sheet, and the second thermosetting resin composition is impregnated in a second outer region in the thickness direction of the fiber sheet which is opposite to the first outer region;
• and
• (b) arranging the two thermosetting prepreg precursor sheets on top of each other such that the first outer region of the fiber sheet of one of the thermosetting prepreg precursor sheets faces the first outer region of the fiber sheet of the other of the thermosetting prepreg precursor sheets;
• wherein, in the thermosetting prepreg precursor sheets, the equivalent ratio of the curing agent in the first thermosetting resin composition is higher than the equivalent ratio of the curing agent in the second thermosetting resin composition.

A method for producing a thermosetting prepreg precursor sheet, comprising:

• providing a fiber sheet,
• providing a first thermosetting resin composition comprising a thermosetting resin and a curing agent;
• providing a second thermosetting resin composition comprising a thermosetting resin and a curing agent;
• arranging the first thermosetting resin composition on one main surface of the fiber sheet;
• arranging the second thermosetting resin composition on the other main surface of the fiber sheet;
• and
• impregnating the fiber sheet with at least part of the first thermosetting resin composition and the second thermosetting resin composition;
• wherein the equivalent ratio of the curing agent in the first thermosetting resin composition is higher than the equivalent ratio of the curing agent in the second thermosetting resin composition.