TAGS: Industrial Coatings Automotive Coatings
With an innovation in the production process for AEROSIL® fumed oxides from Evonik, Business Line Coating Additives, these fumed silicas can now undergo wetting and dispersion — processes that previously had to be carried out in two separate systems (dissolver, bead mill) — in a single dissolver step.
Single Dissolver Step
The use of these so-called “easy-to-disperse silica” (E2D) decreases processing times, cleaning times, and production losses. Moreover, omitting the milling step reduces investment and maintenance costs.
In order to test its processing characteristics, rheological effects, and optical properties within a coating system, the standard product was processed using traditional bead milling procedures, while the experimental product was processed exclusively in the dissolver.
The results for viscosity, gloss, haze, and jetness (depth of color) and improvement of scratch resistance (VP RS 920) were all correct within the accuracy of measurement.
The viscosity curves at high and low shear rates were identical within the key range of rising viscosity. This showcases a key advantage of the E2D products: Because they achieve the same level of efficiency and the same optical characteristics, manufacturers do not need to adjust existing formulations, and new formulations can be created according to the same rules as earlier coatings.
Chemically Identical to AEROSIL® Products
In addition, easy-to-disperse versions of fumed silicas are chemically identical to the corresponding AEROSIL® products. An important point to highlight here is that no additives of any kind are used in the production process, making these products just as compatible with coating systems as familiar standard products.
The experimental products that are available for sampling are VP RS 92, VP RS 82, VP RS 85 and VP RS 920 which are the E2D versions of AEROSIL® R 972, AEROSIL® R 812, AEROSIL® R 805, and AEROSIL® R 9200. AEROSIL® fumed silica is mainly used in automotive and industrial coatings to control rheological characteristics, as thixotroping agent, as anti-settling agent and to help in the prevention of rust and corrosion.
Source: Evonik