Лако-красочные материалы — производство

Unmodified low MW silicones (dimethylpolysiloxanes) are used as leveling and surface flow additives. Some modified silicones are also used as surface-flow control agents. Such chemical modifications may be either in the backbone of silicones, by replacing some of the methyl groups with alkyl or aryl groups, or via grafting on side chains, such as polyethylene glycol. Many important properties of silicones such as compatibility, surface-tension reduction, heat sta­bility, slip, and mobility in the paint film can be adjusted through such modifications. They work on the principle of migrating to the surface and eliminating local surface-tension differences resul­ting from solvent evaporation. Often silicone flow additives perform additional functions such as substrate wetting, slip improvement and providing anti-cratering effects. Silicones may reduce surface tension to a great extent, and therefore, overdosing may easily lead to side effects, such as poor wetting by subsequent coats and poor intercoat adhesion and foam stabilization.