With today’s coating technology, there doesn’t have to be a tradeoff between high performance and sustainability. Options are growing for formulators to address continuing demands for more sustainable coatings that meet environmental regulations while also providing exceptional performance.
High solid content polyurethane dispersions (PUDs) can help deliver both sustainability and performance features in water-borne polyamide-based polyurethane coatings.
Coatings formulated with polyamide polyurethane technology provide a number of advantages over competitive technologies, including high hardness and chemical resistance, adhesion in nylon/polyamides, glass and polar surfaces, and hydrolytic and thermal stability.
Comparing the benefits of water-borne acrylics, polyurethanes and polyamide polyurethanes:
- Acrylics (33-55% solids) have higher solids, are typically softer and deliver lower performance.
- Polyurethanes (33-38% solids) have lower solids, are harder and deliver higher performance.
- Polyamide polyurethanes (33-55% solids) have higher solids, are very hard and deliver the highest performance, including very low formulated viscosity.
High solids polyamide polyurethanes also deliver resin and formulation stability, especially compared to commercial high solids polyurethane. In 49° C oven stability testing, commercial polyurethane (starting cP of 6,624) turned solid after only three days, while polyamide polyurethane (starting cP of 196) remained fluid (214 cP) even after four weeks.
It also significantly reduced resin dry time in testing, by as much as 80 percent compared to polyurethane and 85 percent compared to commercial polyurethane with high solids (less than a half hour to dry compared to almost 2.5 hours and 3.5 hours respectively).
In testing on concrete panels, the film build thickness of traditional three-coat systems can be achieved in two coats with high solids polyamide polyurethane technology. A high solid PUD in this type of coating also delivered several other benefits in just two coats, including:
- Exceptional Taber abrasion on par with three-coat polyurethane for average weight loss and significantly lower average weight loss than two-coat high-solid commercial urethane.
- Outstanding Konig hardness in standard ASTM D4366 testing for hardness of organic coatings by pendulum damping, similar to Taber abrasion testing (hardness on par with three-coat polyurethane and significantly harder than two-coat high-solid commercial urethane).
- Black heal mark rating of 8 out of 10, which is one point higher than three-coat polyurethane and five points higher than two-coat high-solid commercial urethane.
- The same high gloss in all three systems.
- Strong chemical resistance with only two coats.
High-solid content PUDs (up to 50 percent solids) are available now to advance coating capabilities as never before. When used to formulate high solids water-borne polyamide-based polyurethane coatings, a number of sustainability and reduced cost and labor benefits emerge, ranging from shorter dry time and fewer coats with thicker film to lower VOCs to stable resins and high gloss, among other properties.
When formulating high solids polyamide polyurethanes into a coating, solvent selection is critical to get the best balance of sustainability and performance properties.
Lubrizol can collaborate with you to integrate higher-solid content PUDs, including our line of Aptalon™ Polyamide Polyurethane technology into your advanced coatings.