Powder coatings are solvent-less solid formulations which are electrostatically applied to a surface, heated to a molten state and cured to a final durable film coating. For heat-sensitive substrates such as wood, medium density fiberboard (MDF) and plastics, a resin with a low melting temperature and good flow characteristics and a suitable cure mechanism are required. The market for powder coatings continues to expand and replace traditional liquid-based paint systems as the technology improves particularly regarding lower temperature cure.
Battelle successfully developed and demonstrated a novel low-temperature cure powder coating resin which utilized a soy-based resin with a conventional triglycidyl isocyanurate (TGIC) cure chemistry for the mentioned temperature-sensitive substrates (FY20 USB Project# 2040-362-0722). However, due to tighter supply chains and hazard regulations in Europe prohibiting TGIC use, there is an increasing demand for non-TGIC cure options. In response, Battelle proposed to adapt its resin technology for a UV-cure system as an alternative to the thermal TGIC-cure chemistry. This development intended to retain advantages of the inherent chemical and physical properties discovered with soy-based resin while introducing the fast-curing and higher processing throughput of a UV-cure powder coating without the use of the TGIC curative. A UV-cure resin will enable a sustainable soy-based option to address European furniture markets served by companies such as IKEA requiring a non-TGIC coating system.
In FY24, Battelle has evaluated strategies to introduce UV-cure functionality to soy polyester-amide base resins. The modified resins displayed similar thermal and melt properties to the previously developed resins which enabled the desired low temperature processing and low temperature melt flow on substrates. Selected resin candidates were transferred to ChemQuest Powder Coating Research (CQPCR), for formulation and coating evaluations. In the development process, multiple rounds of resin synthesis, formulation and coating evaluation were performed to improve the coating properties by increasing the UV-cure functionality level. In the next phase of work, Battelle will focus on further refining the resin chemistry, optimization of the powder formulation and scale-up of the resin for industry sampling and evaluation.