Radical-curable seal member for fuel cell

A radical-curable seal member for fuel cell, comprising a crosslinked product of a radical-curable composition and having a glass transition temperature (Tg) of −40° C. or lower, wherein the radical-curable composition comprises:

• (A) (Meth)acrylic polymer having a (meth)acryloyl group at a molecular chain end,
• (B) Monofunctional (meth)acrylic monomer,
• (C) Polyfunctional (meth)acrylic monomer, and
• (D) Radical polymerization initiator,
• wherein the radical-curable composition contains 20 to 90 weight parts of the component (B), 1 to 10 weight parts of the component (C), and 0.01 to 10 weight parts of the component (D) with respect to 100 weight parts of the component (A), and
• a weight ratio [(B)/(C)] of the component (B) with respect to the component (C) is 4 to 24, and a content [(C)/{(A)+(B)+(C)}] of the component (C) with respect to a total of 100 wt % of the component (A), the component (B), and the component (C) is 1 to 7 wt %.