With an innovative manufacturing process, Evonik has developed four new fumed silicas from the AEROSIL® family that are much easier to disperse.
At its site in Hanau, Germany, Evonik's Coatings Additives business line has used an innovative process technology to develop four new fumed silicas - AEROSIL® E 805, AEROSIL® E 812, AEROSIL® E 972 and AEROSIL® E 9200 - which are much easier to disperse.
Using the new products, formulators can omit the grinding step - reducing time and costs - for example with a bead mill, when incorporating them into paints or coatings. At the same time, AEROSIL® E retains all the proven properties of the corresponding standard additives AEROSIL® R 805, AEROSIL® R 812, AEROSIL® R 972 and AEROSIL® R 9200.
The four new E2D (easy to disperse) products, as their alternatives in the standard range, are suitable for rheology control in both pigmented and clear coating formulations. The rheological properties of both product groups are the same, but AEROSIL® E is easier to disperse.
AEROSIL® E additives are mainly suitable for application on wood, plastic, automotive and general industrial coatings. AEROSIL® E 972 is more universally applicable; while the other silicas are intended for specific applications - for example, AEROSIL® E 812 and AEROSIL® E 805 are suitable for automotive OEM clear coatings and AEROSIL® E 9200 is mainly used for special scratch resistance.
Evonik has already started manufacturing the new product range at the Hanau site and a new fumed silica production plant in Rheinfelden is under construction.
The advantages of AEROSIL® E
At one time, the dispersion process for rheological additives, like fumed silica, was complex and time-consuming as paint manufacturers had to grind silicas in a long grinding step using a bead mill to ensure they were dispersed homogeneously in the formulation and could thus develop their full rheological potential. Now, using the new AEROSIL® E products, the use of an energy-intensive bead mill is no longer necessary. "We have relieved our customers of this additional work," says Maximilian Morin, head of the Industrial & Transportation Coatings market segment. "This is because the new silicas can be dispersed in just a single grinding step using a dissolver”.
The easier dispersibility of additives reduces processing times, energy consumption in production and the amount of labour and of the materials required for maintenance and cleaning of the machine. This makes the process more efficient and sustainable.
Finally, AEROSIL® E products can be added to the finished coating at a later stage. "This allows the formulator to control and adjust the rheology at any time," says Maximilian Cornelius, Head of Application Technology AEROSIL®. "This is unique."
The manufacturing process of this new generation of additives should not be limited to these four new AEROSIL® E products. "Therefore, our goal is to use the innovative technology to offer customers other additives that are easier to disperse in the future."