K-KAT^® Non-tin Catalysts for Urethanes

Amines and organometallic catalysts are commonly used as accelerators in the polyol/isocyanate reaction to produce polyurethanes. When formulating a polyurethane coating, it has been found that both performance and properties can be affected by the choice of catalyst.

Amine catalysts are typically used in foam applications. Their catalytic activity accelerates the reaction of aromatic isocyanates with water and alcohols, releasing carbon dioxide. Use of amines in coating applications, however, is generally not acceptable because of their negative effect on film properties, especially yellowing.

King Industries has developed a range of catalysts for isocyanate-hydroxyl crosslinking that are based on bismuth, aluminum and zirconium metal chelates and complexes. These K-KAT catalysts are not only environmentally more acceptable than organotin compounds, but can offer performance advantages as well.

Specific K-KAT catalysts can be selected to enhance these advantages, including reduced water reaction, improved pot life, faster cure, improved catalysis in cationic electrocoating and reduced hydrolysis of ester groups.

Unique Non-tin Catalysts

K-KAT 348, XC-B221, XC-C227 and XK-601 - Bismuth Carboxylate Catalysts Provide properties similar to DBTDL. They are particularly effective in blocked isocyanate and elastomer systems.

K-KAT 4205, 6212, and A209 - Zirconium Catalysts can offer fast, selective catalysis of 2K urethane coatings.

K-KAT 5218 - Aluminum Chelate Catalyst is used in 2K systems where extended potlife is desired.

K-KAT XK-602 - Metal complex designed for powder coatings.

K-KAT XK-604 - Mercury Replacement Catalyst based on a proprietary organometallic complex.

PRODUCT	Composition	% Metal Complex	Attributes/Uses	Technical Data Sheet
K-KAT 348	Bismuth Carboxylate	75	Similar to DBDTL, particularly effective for  blocked            isocyanates and elastomers
K-KAT XC-B221	Bismuth Carboxylate	100	Improved hydrolytic stability. Especially effective in cationic electro-coatings.
K-KAT XC-C227	Bismuth Carboxylate	37	Resistant to hydrolysis.  Improved potlife & high reactivity in forced dried applications
K-KAT XK-601	Bismuth Carboxylate	100	Most hydrophobic K-KAT. Effective in cationic electrocoating.
K-KAT 4205	Zirconium Chelate 2,4 - Pentanedione	N/A	Good potlife, recommended for ambient cure (not bake/force dry)
K-KAT 5218	Aluminum Chelate Complex Reactive Diluent	65	Excellent potlife with 2,4, pentanedione
K-KAT 6212	Zirconium Complex Reactive Diluent	2	Fast cure, waterborne systems Plural component
K-KAT A209	Zirconium Complex Reactive Diluent	14	Fast cure, waterborne, slow reacting systems Resin synthesis
K-KAT XK-602	Metal Complex	80	Uretdione crosslinked and caprolactam blocked isocyanate powder coatings.
K-KAT XK-604	Organometallic Complex	100	100% solids 2K urethanes for cast elastomers. Similar cure profile to mercury catalysts.