WACKER Presents Sustainable Silicone Resins for New Weathering- and Heat-Resistant Coatings and a New Dispersion for Fireproof Coatings

SILRES^® REN70-M is virtually free of aromatic solvents, thus providing an alternative to conventional binders for extremely heat- and weather-resistant industrial coatings. These kind of silicone resin binders are typically supplied as a solution in aromatic solvents such as xylene. Instead, SILRES^® REN70-M uses 1-methoxy-2-propyl acetate as a solvent, which is biodegradable.

SILRES^® REN70-M offers the ideal combination of hardness and flexibility. As a binder in heat-resistant coatings it effectively protects metal surfaces from corrosion even at high operating temperatures or rapid temperature fluctuations.

The binder dries tack-free even at room temperature. SILRES^® REN70-M can also be fully chemically cured, which takes place via reactive silanol groups. With the aid of a catalyst, complete chemical cure can be achieved in just 20 minutes at 180 °C, which means the silicone resin cures faster than comparable products. The cured binder easily passes solvent rub tests. This makes SILRES^® REN70-M ideally suited to use as a binder in coatings for industrial plants, pipework or engine parts. SILRES^® REN70-M also provides the resistance needed for coatings on barbecues, chimneys, wood-burning stoves or gas-fired incinerators.

SILRES^® IC 235 – An Aromatic-Free Intermediate

WACKER presents a new polysiloxane-based intermediate for optimizing the chemical and physical properties of organic binders in industrial coatings. SILRES^® IC 235 consists of a methoxy-functional phenyl methyl polysiloxane with a low molecular weight distribution. The intermediate SILRES^® IC 235 does not require any aromatics.

The new silicone resin has been designed so that an addition of only 15 percent is sufficient to improve the UV and weathering resistance of the organic binder in a coating system – without detracting from its mechanical properties. Weathering and lab tests have shown that SILRES^® IC 235 provides for substantially improved gloss retention, greater protection against weathering and an extended useful life. Additionally, a higher percentage of silicone in the binder improves the heat resistance of the coating system up to 300 °C. SILRES^® IC 235 is used, for example, in coatings for static metal structures such as bridges or railings and in industrial plants.

VINNAPAS^® EZ 3067 for Intumescent Coatings

Intumescent Coatings are special fire protection coatings that swell on steel girders to form a jacket that slows the rate at which load-bearing structural parts of a building melt or buckle in the event of fire. Applied in a thickness of just one to four millimeters, the coating expands on exposure to heat, forming a layer of foam that is roughly ten to 100 times the original coating thickness. As the foam has an extremely low thermal conductivity, the temperature inside the coating rises more slowly. The steel girder is protected from the heat for a set length of time and so remains structurally stable for longer.

The new VINNAPAS^® EZ 3067 polymer dispersion shows particularly vigorous foam development and expansion, and long-term foam stability. It also enhances the adhesion and strength of the coatings, ensuring that the protective layer adheres firmly to the substrate and acts as a heat barrier for a set time. Without the binder, the foam layer would be too brittle and would have inadequate adhesion to the steel substrate. The dispersion is water-based and free of organic solvents or additives such as plasticizers. If suitably formulated, such a highly fire-resistant coating can attain fire resistance classes as high as F120 (heat protection for up to 120 minutes).

Visit WACKER at ECS 2017, Hall 1, Booth 1-510.