Extending Coatings with Alumina Trihydrate (ATH)

To "extend the coating" is to lower the cost per gallon while maintaining aesthetics, jetness, chemical resistance, flexibility and durability.  In some cases, "extending the coating" means replacing titanium dioxide (TiO2).  In other instances, it means replacing the resin as well.  In both cases, cost is lowered on a per gallon basis because alumina trihydrate (ATH) is lower in density than TiO2 or barium sulfate.

Without the right extender, it can be difficult to maintain performance when the resin portion is reduced.  ATH is used as an extender since it is inert and has low density and relatively low oil absorption.
The selection of the extender will depend on a variety of factors:

  • The dry film thickness of the coating (DFT)
  • Gloss of the coating
  • Exterior / Interior
  • UV Cure Fillers

    SpaceRite® S-3 is recommended as an extender in the following UV cure applications to lower the cost of these systems without sacrificing color, durability or gloss:

  • Clear UV cure coatings and overprint varnishes
  • White UV coatings and inks
  • Pastel to deep tone UV coatings and inks
  • Thicker UV cure systems to improve the cure rate
  • For more information on SpaceRite S-3, click on our brochure at right. 

    For applications other than UV cure coatings, Huber supplies its SpaceRite® S-11 and SpaceRite S-3 double precipitated ATH grades.  These are inert, extremely high brightness products which can extend deep tone coatings without impacting the color.