Once considered inferior to solvent based coatings, water based coatings have seen rapid technological improvements and increased demand over the last four decades. This is largely in part to tighter regulations regarding clean air standards. While these technological advancements have allowed latex paints to rival the performance of solvent based paints, they have also caused the cost of formulating a latex paint to rise. Luckily, the increased cost of formulating a latex paint can be mitigated by using Capstone™.
What is Capstone?
Capstone™ is a line of VOC and APEO free fluorinated surface active agents, or surfactants, that are extremely effective wetting agents in water based paint formulations.
How Can Capstone™ Reduce Formulation Cost?
When incorporated into latex paint formulations at a very low level (typically 0.01-0.05%) Capstone™ eliminates the need for pigment wetting agents, surface wetting agents, and all other surfactants. By replacing these traditional surfactants with Capstone™ a significant cost savings can be realized. In addition, the reduction in surfactants leads to less foam generation and allows for a reduction in defoamer and even further cost savings.
Guidelines for Reformulating with Capstone™
Because formulations can vary and must satisfy a variety of performance needs, there is no simple one size fits all solution to reformulating with Capstone™ to realize a cost savings. However, to assist in gaining a better understanding of how Capstone fits into the formulation process we have provided the table below with some general guidelines.
Capstone™ can be added in the grind phase to eliminate the need for a pigment wetting agent and defoamer. It can also be added during the letdown phase to improve surface wetting, leveling, and anti-block properties. Selection of the appropriate grade of Capstone™ is dependent on the desired functionality and the phase at which it will be added. The Image below highlights common Capstone™ grades and the functionality that they provide.
Capstone™ for Pigment Wetting
Pigment wetting agents are added during the grind phase and are intended to help replace the air surrounding the pigment particles with the carrier medium which its typically water. Capstone™ FS-30 and Capstone™ FS-31 are non-ionic surfactants that can be added in a very small dosage during the grind phase to improve pigment wetting. The improvement in pigment wetting provided by Capstone™ eliminates the need for other wetting agents and leads to an average of 10X reduction in surfactant usage.
Capstone™ for Leveling & Anti-Blocking
Water-based paints often have issues wetting out low energy surfaces. The large contact angle of latex paint on a surface can cause poor adhesion and surface defects like orange peel, pinholes, and cratering. This is especially a problem when a high gloss finish is required. The use of a leveling agent is typically required to ensure a defect free finish. Capstone™ FS-61 and Capstone™ FS-63 are powerful leveling agents that can be added to latex paint formulations during the letdown phase. An added benefit to using Capstone™ as a leveling aid is that it also provides excellent anti-block properties and eliminates the need for waxes and other common anti-blocking agents in the formulation.
Capstone™ for Dirt Pick-Up Resistance
Latex paints used in architectural applications have a tendency to pick up dirt and oily stains over time. The addition of Capstone™ FS-81 in low-sheen paints and waterborne coatings improves cleanability of oil based stains and improves oil and dirt repellency. Additionally, Capstone™ FS-81 does not interfere with re-coat adhesion or create water repellency. The graph below illustrates the increase in contact angle of oil on a painted surface that is seen when Capstone™ FS-81 is added to the formulation.
Summary & Conclusion
The demand for water-based paints and coatings continues to climb as environmental regulations regarding clean air tighten. Coating manufacturers need to maximize the performance of their latex paint formulations while minimizing production costs. Capstone™ Fluorosurfactants provide superior wetting properties to traditional surfactants and are recommended as a cost-saving replacement for alcohol ethoxylates, APEO, and other traditional wetting agents. Additionally, adding Capstone™ to latex paint formulations eliminates the need for many other additives including defoamers, leveling agents, and anti-blocking aids.