Curing agent for powder coatings, the powder coating composition, this curing agent comprising and powder coating film

摘要

PROBLEM TO BE SOLVED: To obtain the subject curing agent containing a specific carbodiimide compound as the main component, capable of lowering baking temperature in coating operation and preventing the generation of toxic volatile organic compounds when heated without impairing its excellent curability. ;SOLUTION: This curing agent contains, as the main component, a compound of formula I (R₁ and R₂ are each a residue of aliphatic, alicyclic or aromatic monoisocyanate; (n₁) is 2-50), pref. a compound of formula II (R₄ and R₅ are each the same as R₁ and R₂, respectively; R₃ and R₆ are each a residue of aliphatic, alicyclic or aromatic monisocyanate; (n₂) is 0-48). The above compound is pref. 40-200°C in melting point, and it is recommended that this curing agent also contain a conventional curing agent, specifically an aliphatic or aromatic amine.;COPYRIGHT: (C)1999,JPO