Fast-curling, high strength, two-part sealants using acetoacetate-amine cure chemistry

A sealant composition comprising;

• a) a first part including an acetoacetate-terminated component comprised of oligomers or polymers made from the acetoacetylation reaction of polyols, said polyols being polyethers or polyesters or both, at least 70 weight percent of said acetoacetate-terminated oligomers or polymers having a molecular weight of 500 to 10,000 and;
• b) a second part including an amine-terminated component comprised of oligomers or polymers made from polyethers or polyesters or both, at least 50 weight percent of said amine-terminated oligomers or polymers having a molecular weight of 500 to 10,000,
• c) 0 to 30 weight percent of acetoacetate-terminated species made from the acetoacetylation reaction of polyol molecules of low molecular weight, said polyol molecules having molecular backbones of atoms selected form one or more of carbon, oxygen, and nitrogen, said acetoacetate-terminated species having a molecular weight less than 500,
• d) 0 to 50 weight percent of amine-terminated species having molecular backbones of atoms selected from one or more of carbon, oxygen, or nitrogen, said amine-terminated species having a molecular weight less than 500,
• said acetoacetate-terminated component of 500 to 10,000 molecular weight and said acetoacetate-terminated species of less than 500 molecular weight having two or more terminal acetoacetate groups, and
• said amine-terminated component of 500 to 10,000 molecular weight and said amine-terminated species of less than 500 molecular weight having two or more terminal amine groups, and wherein said sealant cures into a polymeric network within 24 hours of mixing said two parts;
• at least one of said two parts further including carbon black and a transesterification catalyst, wherein said transesterification catalyst accelerates the reaction of the acetoacetate-terminated component with amine-terminated component.