Heat Shield for Cookware - Wacker Chemie AG

Heat Shield for Cookware

Products coated with silicone polyester resins include exhaust systems and other molded parts. Crosslinking takes place during baking, where the coating layer is heated to between 250 °C and 280 °C for around 10 to 15 minutes.

WACKER provides the Milan company with more than just silicone resins, however – applications expertise is also part of its portfolio. “We support our customers with recommendations for basic formulations,” Haas explains. “In other words, we provide information for a specific formulation, and they can use that information for developing their own formulations.” This support can shorten development times – in some cases by more than half – and saves money. “We bring our many years of experience to bear to help our customers develop innovations,” Göblmeier adds.

Over the past year, Benasedo has been working with WACKER to launch a number of innovations – in part to strengthen its competitive position on the market. “We have no doubt that better quality is what will prevail on the market,” says Trombetta, which is why Benasedo is increasing its investments in the development process. “We want to keep improving the heat resistance of some of our resins – and we want to develop new ones,” the chemist explains. “Our focus also covers water-based coatings, because demand for these is growing on markets where sensitivity to environmental issues is high. So, we’re building on the support from WACKER and its wide range of intermediates and silicone resin emulsions.”

SILRES® MPF 52 E: Heat-Resistant and Low-Solvent

Alkoxy-functional phenyl methyl silicone resins have been used as binders in heat-resistant coatings for quite some time. SILRES® MPF 52 E is among those binders which contain a silicone resin of this type – one in liquid form. In the new binder, however, the resin is finely dispersed as tiny droplets in an aqueous medium.

This type of formulation has only become possible over the past few years: it used to be the case that an aqueous emulsion of an alkoxy-functional – and consequently reactive – silicone resin could not be stabilized without additional solvent. By using a suitable nonionic emulsifier and skillfully selecting the silicone product, WACKER scientists found a way of formulating a workable, low-solvent emulsion.

Despite its high solids content of 55 to 65 percent, SILRES® MPF 52 E has a low viscosity and can thus be easily processed into coatings by conventional means. Here, it must only be observed that the shear forces on the binder are not too high. Applications tests carried out at WACKER show that SILRES® MPF 52 E is highly suitable as the sole binder for the manufacture of heat-stable coatings. Aqueous formulations of the new binder are tack-free after only 15 minutes.

After baking, sample formulations that contain small aluminum flakes as pigments can resist temperatures as high as 500 °C. The thermal stability of black-paint sample formulations was slightly lower at around 400 °C. The baked coatings adhere well to metal surfaces, exhibiting good chemical and abrasion resistance, losing hardly any gloss after thermal stressing and remaining hard, even in the heat.

The binder can also be used to formulate water-based coatings that, when fully cured, meet the food regulatory requirements of the German Federal Institute for Risk Assessment (BfR) and the US Food and Drug Administration (FDA).

The use of heat-stable coatings based on SILRES® MPF 52 E is thus not restricted to technical objects; they are also suitable for coating cooking utensils, kitchen appliances, barbecue grills and raclette sets.

As Walter Pisoni, a sales manager for WACKER in Italy, goes on to observe, “Of course, sustainability is also becoming increasingly important in the paints and coatings industry.” To make coatings in household appliances, for instance, Benasedo needed a product that would not exceed allowable limits for methanol and VOCs (volatile organic compounds). WACKER experts helped their colleagues in Milan develop a low-VOC resin: “Collaboration on the project was very close and straightforward – we were on the phone with each other every day,” recalls Luciano Pau, Benasedo’s sales manager. “Their technical staff gave us good advice, and often came to help us right on site.” Thanks to this spirit of open collaboration, the two companies managed to develop a product meeting all EU environmental standards within just one year.