Blocked polyisocyanate composition and one-pack thermocuring resin

Abstract

Disclosed is a blocked polyisocyanate composition comprising: a blocked polyisocyanate obtained by blocking the terminal isocyanate groups of a two or more terminal isocyanate groups-containing polyisocyanate derived from at least one diisocyanate selected from an aliphatic diisocyanate and an alicyclic diisocyanate with a blocking agent comprising at least one active methylene compound selected from a malonic diester and an acetoacetic ester; and a salt of a basic compound with an acidic compound, or a mixture of the salt with the basic compound or the acidic compound, the composition having a pH value of from 1 to 8.5. The blocked polyisocyanate composition of the present invention not only exhibits high stability even under high temperature conditions, but also is capable of maintaining such high stability for a prolonged period of time. The blocked polyisocyanate composition can be combined with a polyol to provide a one-pack thermocuring resin composition which exhibits not only excellent storage stability but also excellent curability even under low temperature conditions, which therefore can be advantageously used as various coating materials, adhesives, sealing agents and the like.