Powder coatings storage temperatures

A new, solid, heat-reactive resin based on bisphenol A was introduced recently (10) that is usable after even a year in storage at ambient (70-80 °F) temperatures. This resin polymerizes well at common curing temperatures of 300-400 °F and may be formulated into both solution and powder coatings (11) as will be discussed. 

A storage device that couples a high-temperature hydride to a phase change material has been tested by Arthur D. Little Inc. This system uses the heat released during hydrogenation to melt the material. In the reverse process, the released solidification energy is taken to liberate the hydrogen from the hydride compound. The material used is a Mg powder coated with Ni by means of chemical vapor deposition. The system was successfully tested as an essentially isothermal and isobaric process [29]. 

Most paints are supplied as liquids that are applied by different methods, using various types of equipment (see Chap. 8). The properties and uses of powder coatings are described in Section 3.4. Once applied, the wet paint film must dry to a hard solid film. Paints that dry at ambient temperature (air-drying paints) may be force-dried at temperatures up to 100 °C. Other types of paints require higher temperatures (120-220°C) for film formation that involves reaction of two and more binder components. Thus, the paint formulator has to consider both the properties of the liquid film and those of the final dry film. Liquid film properties have to be considered during storage, application, and curing. 

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