Dynasylan® 40 is a ethyl silicate with a silicon dioxide content of approximately 40 - 42 % upon complete hydrolysis (the Si content of Dynasylan® 40 is calculated as SiO2).
Similarly to Dynasylan® A, Dynasylan® 40 is used to deposit silicic acid formed as a result of complete hydrolysis. The resulting silicic acid bonds well to many inorganic substrates, such as glass, ceramic, metal, fillers, pigments and synthetic fibers. The deposition of a thin SiO2 layer improves the chemical and thermal stability and mechanical properties. Other applications are: crosslinker component in cold-curing silicone rubber systems binder, especially as a Dynasylan® 40 hydrolysates for molds used e.g. in the precision foundry industry. hardening component in dentistry for impression materials and as binder for embedding material Dynasylan® 40 is also used as starting material for sol-gel processes. It is usually used in conjunction with alkylsilanes (e.g. Dynasylan® PTEO) organofunctional silanes and/or organic precursors(e.g. organic resins) to form siloxane networks. This makes it possible to obtain highly scratch-, abrasion- and chemical-resistant coatings. Dynasylan® 40 is immiscible with water, so hydrolysis therefore requires a cosolvent as solubilizer. Mineral acids and ammonia are suitable as catalysts. Dynasylan® 40 or its hydrolysates are also the binder component for 1- and 2-pack zinc dust paints, crucial for corrosion protection on steel. Dynasylan® 40 as binder for 1-pack zinc dust paints The hydrolysis and condensation reaction of Dynasylan® 40 is catalysed through via basic compounds such as diethanolamin. Dynasylan® 40 zinc dust paints or binders catalysed in such manner have an excellent storage stability (under exclusion of moisture). Through addition of a physically drying binder, such as an acrylate, the initial hardness of the coating can be improved dramatically. Such zinc dust paints cure rapidly with ambient humidity through hydrolysis and condensation. Further information can be found in the product information of Dynasylan® MKS and S 100.