Waterborne coating and paint systems are among today’s most commonly chosen technologies to maintain or beautify wood floors. Waterborne systems are easy to apply, emit low odor, and provide long-lasting protection. When interviewed about the current water-based options on the market, however, professionals who apply these coatings and paints highlighted several areas needing improvement. These areas focused on appearance, relating to pore and grain visibility and color stability.
The Problem with the Primers
As with any other coating or paint system, conducting appropriate surface preparation and using wood floor primers is critical. This is especially true for wood coatings and paints, given the porous, nonuniform surface of wood. Many primers and intermediate coats used on wood flooring today are acrylic or polyurethane dispersions. Often, these dispersions must be pH stabilized by surfactants or amines. Unfortunately, these additives can react with the acidic-extractable materials in many wood species and cause discoloration that becomes apparent with the paint or coating. In addition, acrylic wood floor primers contain latex particle sizes that are quite large, in most cases between 100 and 1000 nm in diameter. When applied, these particles are too large to penetrate the surface of the wood adequately. This lack of penetration into the surface of the wood leads to poor colored-stain acceptance and imparts a nonuniform grain and pore image. To improve upon the appearance aspects important to the consumer, primers should be formulated with binders that are near neutral pH and have a small enough particle size to penetrate the porous surface of the wood floor.
Enhancing Wood with Eastek™
Eastek™ polymer dispersions are the ideal solution to the primer problems listed above. These sulfopolyester dispersions from Eastman have two key features that make them a perfect binder for coating and paint primers used on wood floors: a neutral pH and exceptionally small particle sizes. Understanding how the sulfopolyester is dispersed and stabilized in water further explains these key features.
Neutral pH
The dispersed sulfopolyester in Eastek™ polymer dispersions is electrostatically stabilized without needing amine-neutralizing additives or surfactants. As a result, the viscosity of primers and coatings formulated with Eastek™ is independent of pH. Thus, adjustments to viscosity during application are not necessary. In addition, reactions with acidic materials naturally present in wood, which cause color change, are reduced.
Eastek™ Viscosity over Varying pH
Small Particle Size
The sulfopolyester polymer particles in Eastek™ polymer dispersions have an average particle size of 20 nm. This small particle size is ideal for penetrating the surface of wood flooring. The improved penetration ensures uniform color and stain acceptance. It also facilitates better crosscut adhesion, providing higher durability to the primer and the paint or coating applied over it. In addition, the small particle size causes floor primers and coatings formulated with Eastek™ to be nearly transparent. Unlike high-solids acrylic dispersions that are opaque and milky during application, floor primers made with Eastek™ are nearly translucent and allow the applicator to instantly observe the wetting and appearance of the surface when they apply the primer. This ensures fewer areas of overlap and creates visible lap marks on the floor.
Comparison to Other Waterborne Polymers
Formulating with Eastek™
Formulating floor primers with Eastek™ is relatively straightforward. Since the sulfopolyester polymers in Eastek™ are electrostatically stabilized, there is no need for stabilizing additives and surfactants. Eastek™ dispersions range from 30% to 33% solids and can be easily diluted by adding deionized water. Formulations based on Eastek™ can be tinted using conventional pigment dispersions for wood. Most Eastek™ products will also form films without the use of a coalescent because the sulfopolyester is plasticized by water. For higher Tg grades like Eastek™ 1200, butyl glycol can be added as a coalescent if necessary.
Summary and Conclusion
The unique characteristics of Eastek™ polymer dispersions make it an ideal binder for waterborne wood floor primers, which provide value to all partners in the value chain. By choosing Eastek™, the primer formulator may reduce the additive package and formulate an amine- and surfactant-free primer that wets out well on porous surfaces. Next, the professional who will apply the primer can achieve a better experience in working with a water-based primer that shows immediate results, dying well with no grain raise and not leaving a poor image due to the clarity of the primer. Lastly, the floor owner gets to enjoy a wear-resistant floor that will not fade or change color over time. Contact us below to request your sample of Eastek™ today to test the difference for yourself.
