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 due to tighter regulations regarding clean-air standards, especially within the architectural paint market. While these technological advancements have allowed latex paints to rival the performance of solvent-based paints, they have also caused formulating costs to rise. Luckily, the increased cost of formulating a latex-based paint can be mitigated by using Capstone™ surfactants.
What is Capstone?
Capstone™ is a line of VOC- and APEO-free, fluorinated surface active agents, or surfactants, that are extremely effective nonionic and anionic wetting agents in water-based paint formulations. Capstone™ is available as anionic, amphoteric, and nonionic surfactants.
How Can Capstone™ Reduce Paint Formulation Cost?
When incorporated into latex paint formulations at a very low level (typically 0.01-0.05%), Capstone™ reduces or eliminates the need for pigment and surface wetting agents, and all other surfactants. By replacing these traditional surfactants with Capstone™, significant cost savings can be realized. In addition, the reduction in surfactants leads to less foam generation and allows for a reduction in defoamer, offering even further cost savings for latex-based paint formulations.
Guidelines for Reformulating Paints with Capstone™
Because formulations can vary and must satisfy a range of performance needs, there is no simple one size fits all solution to reformulating with Capstone™ to realize cost savings for latex-based paints. However, to gain a better understanding of how Capstone works into the paint 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 in paints. 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 to the paint. The image below highlights common Capstone™ grades and the functionality that they provide.
Capstone™ for Pigment Wetting in Paints
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 is typically water. Capstone™ FS-30 and Capstone™ FS-31 are nonionic surfactants that are APEO-free, VOC-free, and nonflammable. These 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 aids and offers an average of 10X reduction in surfactant usage.
Capstone™ for Leveling & Anti-Blocking of Paints
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-63are anionic surfactants and are powerful leveling agents that can be added to latex paint formulations during the letdown phase. Both Capstone™ FS-61 and FS-63 grades are APEO-free. While the FS-61 is also VOC-free, FS-63 is based in isopropanol but has a higher solids content, provides better surface tension reduction, and can provide better oil repellency and easy-clean properties than FS-61. An added benefit to using Capstone™ as a leveling aid is that it also delivers excellent anti-block properties and eliminates the need for waxes and other common anti-blocking additives in the formulation.
Capstone™ for Paint Dirt Pick-Up Resistance
Latex paints used in architectural applications tend to pick up dirt and oily stains over time. The addition of Capstone™ FS-81, an APEO-free nonionic surfactant, in low-sheen paints and water-borne coatings improves cleanability of oil-based stains and improves oil and dirt repellency. Additionally, Capstone™ FS-81 does not interfere with paint 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 tighten regarding VOCs and clean air. Coating manufacturers need to maximize the performance of their latex-based 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 common wetting agents. Additionally, adding Capstone™ to latex paint formulations eliminates the need for many other additives, including defoamers, leveling and pigment wetting agents, as well as anti-blocking aids. Contact us below to have our product experts schedule time to discuss your paint application and the right grades of Capstone™ for you.
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