A curing-type coating-agent composition according to the present invention contains: Component (A) including a urethane adduct compound exhibiting weatherability in an amount of from 99 to 65 parts by mass; Component (B) comprising a reaction product between a colloidal silica and an alkoxysilane compound having a maleimide group in an amount of from 1 to 35 parts by mass; a radical-polymerization initiator serving as Component (C) in an amount of from 0.1 to 10 parts by mass; an ultraviolet absorber serving as Component (D) in an amount of from 1 to 12 parts by mass; and an organic solvent serving as Component (E) in an amount of from 10 to 1,000 parts by mass; with respect to a sum of Component (A) and Component (B) being taken as 100 parts by mass.The composition according to the present invention demonstrates excellent wear resistance and weatherability as a coating agent for plastic substrate, or the like, which is employed outside.