Dynasylan SILBOND HT-28A is a milky-white, low-viscosity pre-hydrolyzed ethyl polysilicate hybrid binder with content ranging from 32.5 to 33.5% silica (as SiO2). The silica content is resultant of a mixture of silica derived from TEOS and other components. This material is formulated for use in two component inorganic zinc-rich primers. Advantages include improved toughness and excellent performance in high-temperature applications. The improved toughness is a direct result of the higher silica content as compared to a ethyl polysilicate binder.
The degree of hydrolysis and acidity have been optimized for the required reactivity and sufficient storage stability.
The hydrolysis and condensation has been started during the production of the binder. Through a shift in the pH this process is accelerated. This shift is achieved by addition of fillers, pigments, additive, or through the evaporation of solvent or exposure to atmospheric moisture. The resulting silicic acid gel cures rapidly at ambient temperatures in air. The process of curing can be accelerated through the addition of alkali catalysts.