PURPOSE: To obtain a composition having a sufficiently long pot life, excellent in workability in coating when used as a coating material and excellent in solvent resistance and hardness, by mixing an acrylic emulsion prepared by a specified method with a water-dispersible polyisocyanate.

CONSTITUTION: This composition contains an acrylic emulsion (A) having a group reactive with an isocyanato group and an acid value of the resin solid of at most 5 and produced by using an emulsifier having a radical-polymerizable unsaturated group for emulsion polymerization and a water-dispersible polyisocyanate (B). As the component A, an acrylic emulsion obtained by the emulsion polymerization of an unsaturated monomer mixture comprising a hydroxylated unsaturated monomer, an unsaturated monomer containing an acidic group and other unsaturated monomer is preferably used.