Use of Hydroxy Functional Fluoropolymer Resins in Free Radical UV Curable Coatings

摘要

Blends of a hydroxy functional fluoropolymer resin with conventional UV curable acrylate diluents were prepared and cured with UV light to form semi-interpenetrating networks (SIPN). After cure the amount of fluoropolymer resin extracted from the films after 5 days with toluene at ambient temperature ranged from 10 to 50 percent of the original amount of the fluoropolymer resin and was proportional to amount of the fluoropolymer resin in the formulation. Thus, some of the fluoropolymer resin was either physically or chemically incorporated into the crosslinked network. A urethane acrylate oligomer was synthesized from a second hydroxy functional fluoropolymer resin. The oligomer gave good mechanical properties when cured and was compatible with standard acrylate diluents. The cure speed of a model formulation containing the fluoropolymer resin based urethane acrylate oligomer was measured by the modulus ratio at doses of 0.2 and 0.5 J/cm~2 and was found to be 0.9. Environmental stability testing using QUV light and 24 hours of water soaking showed no advantage due to the presence of the fluorine substituted oligomer when compared to a conventional urethane acrylate.