19. Emerging Pretreatments

A. Co-Cure Process:  Autodeposition Primer and Powder Coating Topcoat
Speakers:  Omar L. Abu-Shanab & William E. Fristad,  Henkel Corporation

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 finally a sealing rinse.  The latest autodeposition chemistry consists of an epoxy-acrylic hybrid mini-emulsion.  This autodeposited coating after dehydration at 100-120 ºC 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.  Finally, both the primer and topcoat or primer and sealer/-adhesive are chemically “Co-Cured” in a single oven.  This paper describes the autodeposition chemistry, process sequence, and deposition mechanism.  Further, it describes the “Co-Cure” process, showing its performance and simplicity advantages, and illustrates several commercial applications. 

B. Variety of Pretreatments for Zinc Galvanized Substractes
Speaker:  Jake Wiles, Atotech

There are multiple treatments for processing and painting zinc galvanized substrates.  This paper compares and contrasts the different zinc galvanized pretreatment systems, from single stage hand-wand systems to a five - seven stage washer systems, utilizing both conventional phosphate chemistry and new non-phosphate alternatives.  Performance data measuring each pretreatment system against industry specifications/standards are discussed and presented.  Using this performance data will provide a better understanding of which pretreatment system is the best performance-efficient and cost effective system for specific custom coater and captive shop requirements.  This paper also explains how zinc galvanized pretreatment technologies has evolved from conventional processes to non-phosphate alternatives, while still maintaining necessary industry performance requirements.   

C. New Developments in Organic Phosphating/Pretreatment
Speaker:  Mary Carpenter, Carpenter Chemicals

Organic pretreatment has taken a giant leap forward with a new family of products.  They operate on the same principles as the existing organic phosphating line – one step, no water, no waste, no sludge, one minute of treatment time.  The difference is in the performance – much higher corrosion resistance, adhesion and impact resistance.  The reason for this improvement in performance is modification of the bonding characteristics of the polymer to the metal.  The bonding modification will be discussed in detail in the presentation, and specific data will be provided regarding the improvements in performance.  This represents the biggest improvement in the organic pretreatment technology since its inception 40 years ago.