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.
Another product innovation is WACKER’s new binder component for heat-resistant coatings. SILRES® MPF 52E consists of an alkoxy-functional silicone resin emulsion that significantly improves the heat resistance of binders. Unlike existing paint systems, which are classified as dangerous chemicals because of their solvent content, this is a water-based emulsion that permits low-solvent or even solvent-free surface coating systems to be formulated. Manufacturers of heat-resistant coatings thus have available a climate-friendly binder system that is not classified as a hazardous substance. SILRES MPF 52E can be used as either an additive or a binder. For modifying organic polymers, binders formulated with the new silicone resin emulsion achieve heat resistance up to 200 °C. When used as a binder in, for example, aluminum coatings, the coated material can even be processed at up to 500 °C. SILRES MPF 52E also imparts excellent hot-hardness to coatings, i.e. excellent scratch resistance and hardness at elevated temperatures.
WACKER also presents a new building protection product for façade paints and plasters that can be used as both a binder and an additive. In coatings applications, SILRES BS 1303 realizes the typical effects of a silicone resin, such as low water absorption and high water-vapor permeability. But, unlike comparable products, it does not show pronounced surface hydrophobicity. For manufacturers of façade coatings, this opens up entirely new formulation options for adjusting the surface characteristics of the SREP® coatings (silicone resin emulsion paints/plasters). The new building protection product permits coatings to be formulated with moderately hydrophobic surfaces. SILRES BS 1303 is also ideally suited for formulating silicone resin plasters. The product offers excellent compatibility with such systems and can also prevent pin-holing on the plaster.
The new VINNAPAS LL 3019 dispersion based on vinyl acetate-ethylene-vinyl ester copolymers is a versatile binder for high-quality paint and plaster applications. With its good pigment compatibility and extremely good color stability, it offers an impressive solution for exterior paints and renders. Other benefits included improved rheology and excellent processing characteristics. The new product is an ideal binder for a range of applications, from pure dispersion paints, through silicone resin emulsion paints to silicate paints, or alternatively for the topcoat of energy-saving external thermal insulation composite systems (ETICS). VINNAPAS LL 3019 offers an ideal and inexpensive alternative to high-quality styrene-acrylate and acrylate dispersions. The new dispersion is produced without the use of formaldehyde donors or APEO and does not require film-forming agents or cosolvents. It thus allows paints to be formulated with a low VOC content, and is therefore also outstanding for the production of solvent-free, low-emission, matt interior paints and interior plasters.
Another highlight at ECS 2013 is WACKER’s cyclodextrin technology. Cyclodextrins form a cavity in the center of their ring-shaped structure that can accommodate other, predominantly hydrophobic substances to form “host-guest complexes.” This allows them to absorb and transport substances or protect sensitive molecules, stabilize interfaces and selectively improve the properties of polymer systems. These advantages open up many new applications for cyclodextrins in functional systems – they can be used as process auxiliaries during polymerization, as additives for phase-transfer catalysis or for reaction control in the copolymerization of highly hydrophobic monomers. By complexing the aromatic and aliphatic groups of polymer chains, cyclodextrins can selectively influence polymer systems, for example by modifying their weight or influencing their thermal sensitivity. As performance additives, cyclodextrins improve the water solubility without the need to add organic solvents. And as rheology control additives, they selectively modify the flow properties of coatings and can be used together with, for example, associative thickeners to improve the viscosity of the end product.
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