Nanotechnology and Powder coatings - Costs Down, Performance Up - New Technology

NanoProducts Corporation today announced that its technology has been successfully demonstrated in powder coating applications. NanoProducts also announced that its patented nanoscale materials for powder coating applications are now available in commercial quantities sufficient to coat billions of square feet of surface.

Powder coatings are used in numerous applications. They are used as basecoats, clear coats and other layers in automobiles, aircrafts, ships, floors, appliances and in other industrial products. Suppliers and users of powder coatings seek technologies that lower costs and weight while maintaining or improving the appearance and/or corrosion resistance of the finished product.

Conventional powder coating technologies have attempted to reduce the coating thickness to reduce cost and weight, however, such reductions often lead to decreased visual appeal of the finished product. Recent developments in nanotechnology at NanoProducts have demonstrated a compelling breakthrough in powder coating technologies. This breakthrough was publicly announced and  explained by PPG Industries in US Patent Application 2003/0166758 (September 2003, US Patent & Trademark Office). PPG is the world's largest producer of transportation coatings and a leading global provider of industrial and packaging coatings, aircraft transparencies, flat and fabricated glass, specialty chemicals and architectural coatings.

In the patent application, PPG reports that just a 1% (by weight) addition of NanoProducts’ complex oxide nanoparticles significantly enhances the performance achievable with powder coatings. PPG explains, “Coating compositions are typically required to provide optimum properties, e.g. appearance and/or corrosion resistance, at a minimum film thickness. For example, in the automotive industry, clear topcoats are typically required to have cured film thicknesses of no greater than 75 microns. Lower film thickness reduce material costs and weight gain of the coated ware. However, as the film build of an applied coating composition is decreased below 75 microns, the appearance of the coating degrades rather precipitously.” PPG’s powder coatings with NanoProducts’ nanoscale materials were found to overcome this problem and offer significantly improved visual performance, even when the coating thickness was reduced. Additional positive attributes of coatings prepared with NanoProducts’ materials was that nanoparticles enhanced the ability to bake high quality coatings of vertical surfaces in addition to the horizontal surfaces. Vertical parts presently tend to have a lower quality appearance than horizontal surfaces.

The PPG patent application extensively studies epoxy-based powder coats. The comparative formulation used for these coats consisted of a functional acrylic, dodecanedioic acid, Wax micropowder from Hoechst-Celanese, Tinuvin and other additives from Ciba-Geigy, antioxidants from Sanko Chemical, methyl dicocaoamine from Akzo-Nobel and a flow additive from Solutia and other sources. The performance of this formulation was studied with and without the presence of NanoProducts’ nanoparticles in order to objectively identify the value-added by nanotechnology. The study measured six parameters to fully study the impact of the nanoparticles. The gloss, haze and DOI of the coating were measured using a Byk-Gardner 20O gloss/haze instrument. A Byk-Wavescan was used to characterize the roughness, longwave and GM Tension values. As PPG explained, “Better visual appearance is generally observed when the gloss, DOI and GM Tension values are higher while the haze, longwave and shortwave values are lower. A few number difference in gloss, haze, or DOI is minimally noticeable; whereas even 0.5 number difference in longwave and GM Tension is visually obvious.”

PPG reports that when contrasted with formulations that did not contain nanoscale materials, coatings prepared from formulations that included 1% (by weight) nanoscale materials from NanoProducts showed significant improvement in performance. Specifically, with nanotechnology, the following characteristics were measured when coating thickness was same:

  • Longwave value dropped by 2.0 points and GM Tension values jumped up about 2.0 points confirming the obvious superior visual performance of nanotechnology enabled coating
  • Substantially similar gloss, haze and DOI
  • Lower shortwave roughness as desired.

Notably, a 53 micron thick nanoparticle-based coating was visually superior to a conventional coating that was about 20% thicker. The ability to reduce coating thickness while enhancing visual appearance offers an opportunity to use less raw materials, lower costs and weight and improve margins.

Posted 2nd November 2003

Tell Us What You Think

Do you have a review, update or anything you would like to add to this article?

Leave your feedback
Submit