Abstract: A curable coating composition has a binder comprising a compound or polymer (A) containing at least one primary or secondary amine group, a compound or polymer (B) containing at least one ethylenically unsaturated double bond activated by an adjacent electron-withdrawing group, and a polymer (C) containing at least two silicon-bonded alkoxy groups. Either (A) or (B) contains at least one silicon-bonded alkoxy group in its molecule. The coating is capable of curing at ambient temperature and humidity both by hydrolysis and condensation of the Si—O—C bonds of the polyorganosiloxane (C) and of the aminoalkyl silane (A) and by Michael-type addition reaction of the amine group of the aminoalkyl silane (A) with the activated ethylenically unsaturated double bonds of (B).