Silicone resins are used as binders for impregnation, lamination and coating applications. Electrical motors, mainly for traction applications, as well as mica-laminates represent the main markets for silicone resin in the field of the electrical insulation. Silicone resin compounds for molded parts are not commercially offered in quantities relevant to the market yet.

Driven by the expected outstanding resistance to thermal stress and UV-radiation, a novel, solvent free, low viscous silicone resin binder has been developed. This was used to iteratively create reinforced compounds, optimized for press forming and pressure gelation. First injection molding trials have been successfully finished as well. It was found that both, a fast, well controlled platinum catalyzed and a rapid peroxide induced hydrosilylation are possible to cure these materials. Necessary additives have been developed.

The paper deals with the chemical composition and the resulting properties of both binder and cured silicone resin compounds. Selected results with respect to the combination of reinforcing fillers as well as to the processability are presented. Optimization of the mechanical properties was achieved by compounding the binder with a special combination of fiber- and particle-shaped fillers. In comparison to earlier presented formulations the latest material shows the desired mechanical properties without an obligatory post curing process. Molded parts are easily removable from the mold without the use of release agents. The material shows outstanding thermal stability in comparison to other polymeric materials. The thermal class was measured to be 220 (R).