Neutral silicone sealants are widely used in construction, glazing, automotive assembly and industrial sealing because of their flexibility, weather resistance and adhesion properties. One important component in these formulations is the silane crosslinker.

Methyltris(methylethylketoxime)silane, also known as MOS or methyl tris(MEKO) silane, is an important crosslinking agent for oxime-cure silicone sealants. It reacts with moisture during the curing process and helps form a three-dimensional silicone network.

When used in moisture-curing RTV silicone formulations, MOS reacts with silanol-terminated polydimethylsiloxane (PDMS). This reaction contributes to the formation of an elastic silicone rubber structure. During hydrolysis and condensation, 2-butanone oxime (MEKO) is released as a by-product.

Compared with acetoxy-cure systems, oxime-cure systems are commonly selected when neutral curing characteristics are required. The crosslinker also plays a role in the curing behavior and final mechanical properties of the sealant.