Stability of Aqueous Polymeric Dispersions for Ultra-Thin Coating of Bi-Axially Oriented Polyethylene Terephthalate Films.

The stability of polyacrylate and polyester based aqueous dispersions designed for ultrathin coating of extruded plastic films, especially bi-axially oriented polyethylene terephthalate (BOPET), was studied. Also, the effect of the gemini surfactant based defoaming/wetting agent on the properties of the dispersions was examined. The addition of the defoaming/wetting agent resulted in reducing the surface free tension of the polyacrylate and polyester dispersion by 15% and 20%, respectively and the initial foam height by 60% and 15%, respectively. At the same time, the agent addition did not compromise the temperature and pH stability of the dispersions. Such modified dispersion can be utilized for ultrathin coating of plastic film used for packaging, to improve their processability, printability, and metallization. [ABSTRACT FROM AUTHOR]