K-KAT XK-633 is a zinc carboxylate catalyst recommended for solventborne or solvent-free 2K PU coatings and 1K blocked isocyanate systems. It is FDA 175.300 compliant.
K-KAT XK-633 can be used in combination with K-KAT XK-651 to provide good through cure of 2K PU systems.
Back end cure
1K blocked NCO