Acid/epoxy reaction catalyst screening for low temperature (120 °C) powder coatings

• Published in: Progress in organic coatings Vol. 52; no. 2; pp. 98 - 109
• Main Authors: Merfeld, Glen, Molaison, Chris, Koeniger, Rainer, Acar, A. Ersin, Mordhorst, Steve, Suriano, Joe, Irwin, Pat, Warner, Ron Singh, Gray, Ken, Smith, Mark, Kovaleski, Kevin, Garrett, Greg, Finley, Steve, Meredith, Debora, Spicer, Mike, Naguy, Tom
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01.02.2005; Elsevier Sequoia
• Subjects: Applied sciences; Catalysis; Coatings. Paints, varnishes and inks; Components, formulation; Epoxy; Exact sciences and technology; Low temperature cure; Polymer industry, paints, wood; Powder coating; Thermal analysis; Yellowing; Catalysis; Thermal analysis; Epoxy; Powder coating; Low temperature cure; Yellowing; Differential scanning calorimetry; Temperature dependence; Ageing; Crosslinking; Experimental study; Coatings; Modeling; Powder; Screening; Formulation; Optical properties; Epoxide; Kinetics; Catalyst
• ISSN: 0300-9440; 1873-331X
• DOI: 10.1016/j.porgcoat.2004.09.004

This paper describes efforts to identify and screen suitable acid/epoxy reaction catalysts for low temperature curing (≤120 °C) powder coatings including tertiary amines, ammonium compounds, and metal complexes. Thermal analysis techniques were developed to aid evaluation of catalyst efficacy and a statistical design of experiments was carried out to study several commercially available catalysts. In three different resin/crosslinker systems, the effect of catalyst type and loading were assessed and ranked in terms of kinetic responses including reaction rate, total heat-of-reaction, and extent-of-conversion. Isothermal kinetics modeling was also used to predict and compare reaction rates over a range of temperatures. Additionally, the susceptibility of each catalyzed system to thermal yellowing upon over-bake was evaluated.