Water based intercoat coating composition and multi-layer coating film-forming method by use of the same

摘要

A water based intercoat coating composition containing (A) a polyester resin comprising, as essential components, an alicyclic polybasic acid (a₁) and/or an alicyclic polyhydric alcohol (a₂), other polybasic acid (a₃) and other polyhydric alcohol (a₄), (B) a blocked polyisocyanate curing agent, and preferably (c) a water-dispersible blocked polyisocyanate curing agent.