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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.

Over the past 60 years, chemical companies have been supplying automotive manufacturers state-of-the-art zinc phosphate conversion coatings which, when applied properly to a metal surface promote excellent paint adhesion and corrosion resistance. Phosphate conversion coatings have undergone many transformations over the years. Now some of their essential components and byproducts are being more tightly regulated under new environmental guidelines. The metal pretreatment industry is now challenged with the task to replace the traditional zinc phosphate coating with the next generation product. This paper will examine the advantages of a new generation conversion coating based on zirconium oxide. The performance and process cost savings will be discussed. This technology has been advancing over the past several years, and in 2007 several successful commercial line trials with this new conversion coating were conducted.

Autodeposition coatings are thin, highly corrosion resistant organic coatings that deposit paint by reaction with the metal surface. The coating deposits only on metallic surfaces, thus allowing coating of just the metal portion of metal-plastic or metal-rubber assemblies. Because it is a chemical reaction with the metal surface, it is possible to evenly paint the inside of tubular and boxed sections, which is where corrosion typically starts. The overall autodeposition process includes cleaning, water rinse, coat, reaction rinse, and cure. The use of a reaction rinse after the autodeposition coating application allows unique properties to be introduced to the coating before curing. This presentation will briefly review the general chemistry of autodeposition. Next it will focus on commercial automotive applications of several newly developed autodeposition coatings. The corrosion performance and physical characteristics of both black and gray epoxy-acrylic coatings will be presented.

Over the past 60 years chemical companies have been supplying automotive manufacturers a state-of-the-art zinc phosphate conversion coating, which when applied properly to a metal surface promotes excellent paint adhesion and corrosion resistance. Phosphate conversion coatings have undergone many transformations over the years, and now some of their essential components and byproducts are being more tightly restricted under new environmental guidelines. The metal pretreatment industry is now challenged with the task of replacing the traditional zinc phosphate coating with the next generation product. This paper examines the advantages of the new generation conversion coatings through performance milestones as well as process and environmental cost savings realized by this technology.

Autodeposition coatings are thin, highly corrosion resistant organic coatings that are deposited in a chemical reaction with a metal surface. Because the autodeposition process deposits a coating only on metallic surfaces, coating of just the metal portion of metal-plastic or metal-rubber assemblies is possible. The overall autodeposition process includes stages of clean, water rinse, coat, reaction rinse, and cure. The use of a reaction rinse after the autodeposition stage is unique among coating processes and allows new properties to be introduced to the coating before curing. This paper will briefly review the general chemistry of autodeposition, and then focus on how corrosion performance and physical characteristics of a recently developed epoxy-acrylic autodeposition coating are designed into the product and how the autodeposition process controls these properties. The role of the organic polymer and the reaction rinse in all the properties will be discussed.

A new series of epoxy-based Autophoretic® coatings have been developed and commercialized at several manufacturing facilities for use as a protective paint film. Autophoretic® coatings are a proprietary series of autodepositing coatings specifically designed for painting ferrous metal substrates. Autodeposition is an immersion process that coats a substrate because of a chemical reaction between aqueous paint dispersion and the base metal. The new epoxy-based Autophoretic® coatings provide a high level of corrosion protection, excellent appearance, and very low VOC. These coatings have automotive approvals and can be used as a sole coat or primer. Typical epoxy-based Autophoretic® coating application conditions and performance data will be presented.

A new epoxy-based Autophoretic® coating has been developed and trialed at a full-scale jobber coating line. Autophoretic coatings are a proprietary series of autodepositing coatings specifically for ferrous metal substrates. An autodepositing coating is one which coats a substrate because of a chemical reaction between the paint and metal upon immersion in the aqueous paint tank. The new epoxy coating has a high level of corrosion protection, excellent appearance, and can be used as either a single coat or primer. Typical epoxy Autophoretic coating application conditions and performance data will be presented.