POLYURETHANE CATALYSTS

Environmental and regulatory considerations are redefining the approach to urethane catalysis. The replacement of tin in the form of organotin catalysts is accelerating due to the known toxicity of tin. The current alternative catalyst system of choice, for good activity and lower toxicity, has been found to be bismuth and/ or bismuth/zinc catalysts. Bismuth and Zinc organics can be used to replace Tin organics in applications including flexible foams, elastomers and CASE, as well as in other urethane applications. Bismuth and Zinc organics can provide other benefits such as low odor and low emissivity in application, as is often not the case with amines. Despite the concern often expressed with "heavy metals" and their assumed toxicity, Bismuth in the form of Bismuth organics does not have this concern in today's regulatory environment.