Resins and additives for powder coatings and alkyd paints, based on renewable resources

Due to limited fossil resources and an increased need for environmentally friendly, sustainable technologies, the importance of using renewable feedstocks in the paint and coatings area will increase in the decades to come. This paper highlights some of the perspectives in this area. Alkyd resins for high-solid paints and reactive diluents, completely based on commercially available renewable resources, were prepared and characterized. Alkyd resins based on sucrose and unsaturated fatty acids or oils showed a low intrinsic viscosity, making them suitable to be used in high-solid alkyd paints. Reactive diluents based on similar starting materials showed excellent properties with regard to thinning behavior and effect on drying characteristics. Powder coating polyester resins were synthesized, starting from isosorbide and diacids. Polyester resins with glass transition temperatures up to 70 deg C were obtained. Incorporation of small amounts of other diols and trifunctional components was found to improve color and coating properties. In order to create completely renewable resin systems, the development of renewable drying agents for alkyds and crosslinkers for powder coatings is in progress.