PEP Review 2006-12
Trends in Coating Resins Made by Emulsion Polymerization
Published: November 2006
In recent years, producers of latex polymers have had to begin complying with new governmental regulations in the United States and Europe that deal with the emission of organic solvents (volatile organic compounds [VOCs]) from architectural coatings. Even though the coatings are water-based, they still typically contain 5-10% organic solvent to function properly. Solvents are required to assist in durable film formation (“coalescents”), provide package stability in cold weather (“freeze/thaw stabilizers”) and to dilute coatings additives. Industry has been challenged to reduce or eliminate these solvents while still providing economical, durable coatings.
To meet the lower VOC regulations, industry has taken several approaches:
- Use additives that contain little or no VOCs.
- Modify film forming polymers so that they need little or no coalescing solvent and/or freeze/thaw stabilizer.
- Use vinyl acetate-ethylene copolymers that form good coating films with little or no organic solvent.
Each of these technologies is discussed in this PEP Review, with examples from the patent literature and information from other sources.