| abstract |
(57) Abstract: [PROBLEMS] To provide a one-pack type urethane coating composition having excellent coating properties such as weather resistance and flexibility, and low temperature curability. SOLUTION: The following blocked polyisocyanate is used as a curing agent. Obtained by reacting an aliphatic and / or alicyclic diisocyanate with a polyhydric hydroxy compound having an average hydroxyl functional group number of 4 to 10, an average isocyanate functional group number of 4.0 to 20, an isocyanate concentration of 5 to 20% by weight, and a number average. Molecular weight 1,200-10,000, viscosity 2 000 to 200,000 mPa.s. Polyisocyanate having an isocyanate cyclic trimer content of 10% by weight or less at s / 25 ° C. is blocked with a heat dissociative blocking agent, and the average blocked isocyanate functional group number is 4.0 to 20, the isocyanate concentration is 2 to 15% by weight, Number average molecular weight 1,500 Blocked polyisocyanate of ~ 15,000. |