Water-based hydrosilylation curable siloxane compositions are commonly used in many industrial processes, for example for paper coating applications. Typically, they are two component emulsion systems where a first emulsion contains a hydrosilylation catalyst and a vinyl terminated polydimethylsiloxane (PDMS) while the other emulsion contains an organohydrogensiloxane. When the two emulsion parts are mixed together, a composition ripening phenomena may occur from the diffusion of the components from the various emulsion particles resulting in premature curing of the composition. As a result a cure inhibitor is typically added in the mix in order to extend the “bath life” of the coating compositions. The final cure of the mix is obtained by the evaporation of the cure inhibitor at high temperature following a coating process.
Thus, a need exists to provide hydrosilylation curable siloxane compositions for use in water based systems that eliminate the need for the addition of cure inhibitors to extend bath life of the coating compositions, and allow for low temperature cure.
USPTO Backgrounds
USPTO Backgrounds