Co-Cure Process: Autodeposition Primer and Powder Topcoat
Autodeposition is an immersion, direct-to-metal coating process that forms a paint film on metal surfaces by a chemical reaction between an aqueous paint dispersion and the base metal. The autodeposition process consists of cleaning, rinsing, organic coating deposition, and a sealing rinse. Conventional pretreatment/primer systems require full thermal cure prior to topcoat application because of volatiles that must be lost during cure. The latest autodeposition chemistry consists of an epoxy-acrylic hybrid mini-emulsion. The chemical combination of a flexible, high molecular weight acrylic with a hard, tough epoxy in a semi-interpenetrating network provides a very low VOC (≤0.03 lb/gal) coating. Upon dehydration ~100°C, the autodeposited coating provides a dry-to-handle, tack-free film with physical integrity. A powder topcoat or sealer/adhesive can be applied to the dehydrated autodeposited coating.