German technical background  VOK-373 leveling agent

Reactive silicone surface additive for solventborne and solvent-free systems. This additive is arranged on the surface of the paint and is fixed on the surface of the paint by reacting its primary hydroxyl groups with the binder.

It is preferred for use in two-component polyurethanes, but is also crosslinked with the following binder systems: alkyd/melamine, polyester/melamine, acrylates/melamine, self-crosslinking acrylates and epoxy. Compared to conventional non-reactive silicones, it offers more permanent surface properties (e.g. improved slip, solvent resistance, weather resistance, anti-blocking and less dust build-up) because it is cross-linked to the coating surface by its reactive groups.

VOK-373 also reduces the surface tension, which necessarily improves substrate wetting, improves leveling and prevents Benard vortexing. Compared to VOK-370, VOK-373, it has twice the number of hydroxyl groups per molecule as the additives above, and as a result, the surface tension is reduced and surface slip is increased much less.

VOK-373 can also be used in UV-crosslinkable wood coatings and furniture coatings. In this application, it significantly improves leveling and, in the case of curtain coating systems, stabilizes the curtain, where the reaction group of the additive is not used.

Chemical composition: Polyether modified hydroxyl functional polydimethylsiloxane copolymer solution

Solvent: 2-propanediol-1-methyl ether

Dosage: 0.1-5%, depending on the required effect

       0.05-0.4% in UV crosslinking systems to improve leveling

Typical physicochemical data: Non-volatile: 50 %