WATER-BASED POLYURETHANE RESIN COMPOSITION AND COATING COMPOSITION COMPRISING THE SAME

摘要

A two-pack type composition which comprises a water-based polyurethane resin coating composition, an internal crosslinking agent, and an external crosslinking agent and which gives a coating film having a higher hardness. The composition gives a coating film improved in gloss even when the external crosslinking agent has been diluted with a high-boiling solvent in order to heighten the mixability of the external crosslinking agent with a main-ingredient emulsion. The two-pack type water-based polyurethane resin composition is characterized by comprising: an ingredient (A) which is a water-compatible polyurethane resin obtained by reacting a diisocyanate compound (a) with a fatty acid having an active-hydrogen group (b) and with a polyol compound (c) to obtain a urethane prepolymer, incorporating a polyfunctional polyisocyanate compound and a succinate type sulfonic acid salt into the prepolymer, neutralizing the mixture, and then subject it to a chain extension reaction; and an ingredient (B) which includes a polyfunctional polyisocyanate compound dispersible in the ingredient (A).