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

A fast-curing sealant composition is made from generally liquid oligomers and has good tensile strength, one hundred percent modulus, Shore-A Hardness, and good insensitivity to water. One part of the sealant composition is generally a polyester or polyether oligomer having acetoacetate end groups or functionalities thereon, whereas the second part is also generally a polyester of polyether oligomer generally containing primary amine end groups or functions. The oligomers are generally of a low molecular weight, as from about 500 to about 10,000, and are modified by compounding with various additives such as carbon black, antioxidants, ultraviolet light inhibitors, and the like. Polyfunctional acetoacetate-terminated molecules having 3 or more functional end groups or polyfunctional primary amine-terminated molecules having 3 or more functional end groups serve to increase the crosslink density and modulus of the compositions. The sealant can be used as a coating or as a caulking type compound. One preferred application is automotive windshield sealant.