SPHERILEX® for matt wood coatings and lower PVC Architectural Systems

Consumers desire a natural wood finish which requires a low-gloss surface as well as a smooth tactile feel. Sustainability considerations push the trend towards water-based systems fulfilling high performance requirements. High mechanical and chemical resistance ensure longevity.

Achieving very low gloss levels especially at 85° can be a challenge since high matting agent dosages often result in unfavourable high viscosity. Combining the new SPHERILEX® DP-0110 with high performance silica-based matting agents, keeps viscosity low, helps to avoid problems with foam entrapment, and boosts matting efficiency. Very low gloss levels at 85° angle and thus favourable sheen properties can be achieved. The combination of an irregularly shaped matting agent and a very small, spherical SPERHILEX® DP-0110 provides a unique uneven surface scattering the light and providing outstanding matting effect without compromising film transparency.

In general, matte surfaces are rather sensitive to mechanical stress. Mechanical stress results in abrasion on the surface or even tearing out some of the particles, reducing the scattering effect and showing as sheen or scratches on the surface. When SPHERILEX® DP-0110 is added, mechanical stress is diverted by the compact, smooth particle protecting the surface and maintaining the surface morphology for optimum light scattering effect.

In applications like furniture or parquet coatings, wear in daily use can easily destroy surface appearance. Use of SPHERILEX® DP-0110 improves scratch and mar resistance, making matte films significantly more durable. The spherical morphology helps to avoid impact damage, supports sliding of objects on the surface, and ensures pleasant touch & haptic.

Burnish resistance indicates low gloss difference after wiping / polishing / surface wear of the film. Mar resistance represents robustness against e.g. fingernails in daily use while mechanical robustness stands for e.g. Mini-Martindale scratch test results.

With sustainability not just being an important topic in wood coatings but also in architectural paints, consumers want painted walls to look like new for as long as possible. Higher durability & less frequent painting results in a lower raw material consumption, paint production and waste generation. Semi- and high-gloss paints have been the “go-to” for durability as higher binder content (lower PVC) is believed to lead to stronger paint films.

On the other hand, flat paints have the ability to hide imperfections in underlying walls. For these formulations, finding the right filler selection can be a challenge: typically choosing hard fillers improves mechanical resistance but with broader size distributions, burnish resistance can still insufficient as large particles are removed, leaving smaller ones with less matting ability. SPHERILEX® precipitated silica particles can dramatically improve the durability of interior architectural paints with an excellent burnish resistance combined with powerful wet scrub resistance.

With the new smaller sized SPHERILEX®, improvement of mechanical film resistance can be achieved in satin and eggshell finishes without impact on gloss & sheen as shown in the following graph.

Impact on gloss & sheen for different particle sizes of spherical silica in an interior eggshell paint; SPHERILEX® spherical silica was used to replace 5% of calcium carbonate fillers.