Protectosil SH is a mixture of ethyl esters of different polysilicic acids for the consolidation of construction material.
Protectosil SH is immiscible with water, so hydrolysis therefore requires a co-solvent such as ethanol, methanol or white spirit. Mineral acids, ammonia, titanates or tin compounds are suitable as catalysts.
Protectosil SH is a colorless, low-viscosity liquid with an SiO2 content of 40 %. The polysilicic acids still have a sufficient content of ethoxy groups, which can be activated by acid- or base-catalyzed hydrolysis. Condensation starts even during hydrolysis, with the formation of relatively large polymeric molecules. During storage of these hydrolysates, condensation continues until a gel is formed, the gelation rate depends on the degree of hydrolysis.
The action of the hydrolysates as binders is based on the continuation of the hydrolysis with subsequent gelation and dehydration to give polymeric SiO2 structures.