Chemical Technology May 2016

WACKER Silicones – New applications for silicone films

by Glynnis Koch

German chemical company, WACKER, operates globally with a network of production sites spanning all key regions, in Europe, the Americas and Asia. WACKER’s silicone division is one of the largest silicone manufacturers worldwide. Its portfolio ranges from silicone fluids, emulsions, resins, elastomers and sealants to silanes, silane terminated polymers and pyrogenic silica.

W ACKER’s silicone products have applications in sectors such as, for example, chemicals, cos- metics, textiles, paper, electronics and medical technology. In 2015, the division generated around 37 % of the group’s sales. Founded in 1914, the Burghausen plant is WACKER’s principal production site and the larg- est chemical plant in Bavaria, employing almost 10 000 people in over 130 production units, on the 2,3 km ² site. All five of WACKER’s business divisions have operations at the Burghausen site, the integrated silicon-based produc- tion system being one of its key strengths. Five main raw materials form the basis for production: metallurgical-grade silicon, rock salt, ethylene, acetic acid and methanol. The portfolio of products manufactured at the site ranges from polysilicon and hyperpure silicon wafers to silicones, silanes and pyrogenic silicas, as well as dispersions and dispersible polymer powders, solid resins, fine chemicals and base materials for the chemical and biotechnical industries. The functional silicone fluids production plant was expanded in 2015, coming on stream in early 2016, and allowing WACKER to meet the rising global demand for ver- satile silicone fluids and emulsions in the coatings, paper, textile, cosmetics and personal care industries — areas where highly specialised functional silicone fluids serve as important intermediates. The plant combines the siloxane

precursor with other raw materials to produce functional silicone fluids. Another recent project involved upgrades to the facilities and technology of the application centre for silicone release coatings, the Dehesive ® Coating Centre. Ultrathin precision silicone film and dEAP technologies WACKER’s silicone films are 100 % silicone. Like all sili- cone rubber compounds, they are heat- and UV-resistant, flexible even at low temperatures and chemically inert. On account of their dielectric properties, silicone elastomers are categorised as electroactive polymers (EAPs). They are capable of responding to electrical stimulation under certain circumstances. This is the case, for example, when the elastomer is present as a non-conducting layer between two electrodes. Thanks also to their uniquematerial properties, precision silicone films are ideal for dielectric electroactive polymers (dEAP) technologies which began in the 1990s. At the time suitable materials and manufacturing processes were not available to produce dielectric films economically in the required quantity and of the desired quality. A process patented by WACKER now enables manufac- turers to begin mass-producing EAP components for the first time. It allows the manufacture of continuous films

12

Chemical Technology • May 2016