PURPOSE: To make base materials hardly influential to the catalytic activity and improve the workability of coating by mixing a block polyisocyanate, a polyol and a specific filler with a solvent.

CONSTITUTION: The title urethane coating material is prepared by blending a film-forming component consisting of a block isocyanate and a polyol, a filler prepared by mixing a curepromoting filler (e.g. barite) having an average particle size of 5-30μm, a moisture content of 0.3% or less and a pH of 8-10 with a cure-retarding filler (e.g. silica) having an average particle size of 5-30μm, a moisture content of 0.3% or less and a pH of 5-6 in the ratio of 8:(2-6):4 by volume, and a solvent. The cure-promoting and cure-retarding fillers regulate the curing reaction.