One of WACKER's highlights at Stand 1-510 is the unveiling of the new VINNAPAS® LL 3112 dispersion, a binder for intumescent coatings. These special fire-protection coatings encase steel girders and swell (intumesce) in the event of a fire, thus delaying the melting or warping of the building’s supporting structure. The coating is usually applied one-to-four millimeter thick and, when subject to heat, foams to tens to hundreds of times its original thickness. Because of the extremely low thermal conductivity of the foam layer that is produced, the temperature in the interior of the coating increases only slowly, so that the steel girders are protected against the heat of the fire for a defined time, and thus retain their strength for longer.
The new VINNAPAS LL 3112, based on vinyl acetate-ethylene-vinyl ester copolymers, shows particularly pronounced foaming and expansion, and long-term foam stability. At the same time, the adhesion and strength of the intumescent coatings are improved, so that the protective layer firmly adheres to the substrate and forms a heat barrier for a limited time. Without the binder, the foam layer would be too brittle and would have inadequate adhesion to the steel substrate, and thus would not be able to function as an insulating layer. Depending on the formulation, the new VINNAPAS LL 3112 now allows highly fire-resistant coatings with fire resistance class F120 to be achieved (heat protection for up to 120 min). Moreover, the water-based binder is free of organic solvents or additives, such as plasticizers, and is manufactured without the use of alkylphenolethoxylates (APEO)-containing materials.