| abstract |
[Problem] In a coating method of a two-coat one-bake system where a clear coat paint is coated after a base coat paint is coated, then these two coated layers are simultaneously hardened, adhesive strength between the two coated layers is to increase in comparison with the conventional method. [Solution] Provided is a coating method; A specific hardener is used in the clear co at paint. The hardener is one containing a polyisocyanate derived from 1, 6-hexamethylene diisocyanate, satisfying all the following conditions: 1 ) Hardener does not virtually include diisocyanate monomer, 2) Viscosity of hardener is not more than 1000 mPa-s/23°C, 3) Content of HDI trimer in hardener is not less than 60 weight %, and 4) Content of HDI dimer in hardener is less than 10 weight %. |