| abstract |
Encapsulated base catalysts in the presence of Michael donors and acceptors result in compositions useful as adhesives, sealants, coatings, elastomers, films, and foams by providing unprecedented control over pot-life and cure rate in a two-part or multi-component system and allowing for use as a one-part composition. Encapsulated catalysts prevent premature reaction of the various reactants during storage and processing and yet, upon the rupture of the capsules by a pre-determined event such as the application of heat, pressure, or solvation, produce rapid cure. Use of encapsulated catalysts gives unprecedented control over pot-life and cure rate over compositions previously contemplated. As such the use of encapsulated catalysts also results in the potential for one-part Michael addition compositions previously not known. The use of encapsulated catalysts also allows for faster green strength development by providing for a very rapid cure upon rupture of the capsules. |