Colloidal Silica-Latax Polymer Nanocomposites for High Performance Coatings

By Stephan Krieger, Ivan Cabrera, Marc Ratering, Thomas Fichtner , Rajeev Farwaha

Nanotechnology will have a significant impact on the paint and coatings market through two channels: the improvement of existing surface coatings and the innovation of new products that deliver the right blend of perform­ance and aesthetics. Nanotechnology is the study of material properties with particle size below 100 nm. Hybrid organic-inorganic composites have attracted widespread attention in the domain of material science.¹

The con­trolled combination of organic and inorganic composite colloids is of in­creasing interest as it enables chemists to create new nano-structured mate­rials with unusual morphology, composition, and properties originating from existing building blocks.

Long lasting performance and good aesthetics are two key performance components for exterior paint. Over time, exterior exposure leads to the ac­cumulation of dirt, air pollutants, dust particles, and debris on the paint film. This results in a dirty appearance which no longer meets the expecta­tions of the consumer. It is well known in the industry that a high level of dirt resistance can be achieved through the use of hard polymers. But, these polymers can also jeopardize film formation, which can then also require high levels of coalescing solvents.

Chemically, there is a wide range of nano material particles that are of interest for use in coatings. To date, the main focus in architectural coatings has been on incorporating nano Si02, Al203, and ZnO to produce func­tional properties such as scratch resistance, mildew resistance, and in­creased durability in the paint film.

This article will document hybrid polymer technology which combines the advantage of one polymer species with another to synergistically create a higher performing class of polymers. Further, this arti­cle will discuss silica-latex hybrid technology and its applications, particularly in the design of dirt pick-up resistant coatings.