TIB KAT 721 W

TIB KAT 721 W – Water-soluble, non-carboxylate bismuth catalyst for polyurethanes

TIB KAT 721 W is a proprietary liquid bismuth catalyst that has two special features: non-carboxylate structure and water solubility. This makes it significantly different from classic bismuth carboxylates such as TIB KAT 716 (bismuth neodecanoate) or TIB KAT 728 (bismuth octoate).

The product is supplied as a 50% active bismuth catalyst in 50% water and is suitable for curing solvent-based polyurethane systems. Like other bismuth catalysts, TIB KAT 721 W is used in a wide range of PU applications, including coatings, adhesives and sealants, elastomers, foams, and plastics. It is particularly suitable for applications where lower toxicity compared to organotin, water solubility, and improved storage stability are critical requirements.

Although its chemical structure differs from that of classic bismuth carboxylates, TIB KAT 721 W exhibits a similar bismuth-typical reactivity profile. The catalyst enables good overall reactivity with a balanced ratio of front-end/pot life and back-end/final cure. As is typical for bismuth catalysts, the final cure is significantly improved by additional or exothermically generated heat.

TIB KAT 721 W catalyzes most PU reactions and exhibits a selectivity similar to tin-based catalysts, especially for polyol-isocyanate and water-isocyanate reactions. In addition, the product offers improved water stability and ensures longer polyol side storage stability compared to bismuth carboxylates.