The newest additions hollow glass microspheres offer improved scrub and burnish properties, viscosity control, thermal insulation and sound dampening characteristics, improved performance and other functional properties previously unattainable to paint and coatings formulators.
No one conventional additive can match the multiple performance benefits of hollow glass microspheres. Because they are made of colorless glass they do not discolor light or pastel formulations. Their hollow glass microsphere structure, low density (0.60 and 0.34 g/cc) and small particle size make them ideal for use as extenders for paint formulations.
Paint that is extended with hollow glass microspheres has a lower viscosity than one filled to an equivalent volume with a non-spherical extender. Spherical particles have a low-energy surface that minimizes friction and drag. As a result, an equal volume substitution of these microspheres for irregularly shaped extenders will decrease the coating’s viscosity. Lower viscosity is a significant benefit in offsetting VOC levels in solvent borne paint. Adding microspheres to a high-VOC paint formulation allows formulators to remove some of the solvent and still maintain a viscosity that facilitates application and spreading properties.
With particle sizes considerably finer than previously available, hollow glass microspheres can be used in thin film coatings to improve integrity. Because glass spheres do not absorb resin, more resin is available to create the film. The result is a tighter and more uniform film with improved durability, even under adverse conditions.
Hollow glass microspheres may also be added to improve hiding properties or to replace some of the titanium dioxide (TiO2). The hollow glass microspheres redirect the angle of light, imparting opacity. Depending on the formulation, equivalent tint strength can be achieved with 5%-10% replacement of TiO2.
