POLYISOCYANATE COMPOSITION HAVING HIGH EMULSIFIABILITY AND STABILITY, AND AQUEOUS COATING COMPOSITION COMPRISING THE COMPOSITION

摘要

A polyisocyanate composition which comprises (a) a hydrophilic polyisocyanate comprising at least one diisocyanate selected from among aliphatic and alicyclic diisocyanates, at least one base polyisocyanate selected from the group consisting of polyisocyanates derived from the above at least one diisocyanate and having two or more terminal isocyanate groups, and a nonionic hydrophilic group composed of on average 5 to 50 repeating ethylene oxide units which is bonded to the base polyisocyanate, wherein the amount of the hydrophilic groups is 2 to 50 wt.% based on the total weight of the base polyisocyanate and the hydrophilic group, and (b) 0.5 to 20 wt.% (based on the total weight of the components (a) and (b)) of a substantially water-free ionic surfactant. This polyisocyanate composition is not only excellent in dispersibility in water, but also highly stable in a state dispersed in water because the reaction of the terminal isocyanate group of the polyisocyanate with water is inhibited. A two-package aqueous coating composition comprising the polyisocyanate composition as a curing agent and an aqueous polyol as a chief material is excellent in pot life, water resistance and so on, and is extremely useful as various aqueous coating materials, adhesives, building materials and sealing compounds.