AQUEOUS DISPERSIONS OF POLYMERIC MICROPARTICLES AND COATING COMPOSITIONS CONTAINING SAME

摘要

An aqueous dispersion including polymeric microparticles having a functionality adapted to react with a crosslinking agent is provided. The microparticles are prepared in two or more stages by emulsion polymerization and include a first stage uncrosslinked polymerization reaction product and a final stage crosslinked polymerization reaction product having a glass transition temperature greater than 25 DEG C. The first stage uncrosslinked reaction product is formed from reactants at least one of which is an acid functional group-containing polymerizable, ethylenically unsaturated monomer. The second stage crosslinked reaction product is formed from reactants which include at least one polymerizable, ethylenically unsaturated monomer having two or more sites of reactive unsaturation, and/or at least one ethylenically unsaturated monomer having at least one self-reactive site. Curable compositions which contain the aqueous dispersions as well as multi-component composite coating compositions are also provided. Further provided are substrates coated with the aforementioned compositions.