Various families of catalysts have been developed for use in semi-rigid polyurethane foam applications (e.g., instrument panels, door panels, etc.). These catalysts range from pure amines to metal salts or coordination complexes. Amino acid alkali metal carboxylates are a new family of catalysts that bridge the properties of the two extremes. This new family of catalysts is potentially more advantageous to occupants of an automobile, due to reduced outgassing, than the more traditional catalysts.
Three specific members of this new catalyst family will be contrasted with both amine and carboxylic acid carboxylate catalysts. Reactivity differences, as measured using both fluidyne and cup methods, are presented. Commonly specified foam properties (e.g., tensile strength, elongation, resistance to tear, compression set, etc.) will also be compared. Lastly, foam-to-shell interactions (e.g., staining and adhesion) will be explored.
This new family of catalysts will allow both the raw material formulator and the OEM material engineer greater latitude in resolving the performance requirements of a polyurethane foam with the limitations of the catalysts. Further, this family of catalysts presents an improved solution to a market that is becoming more “green”.