Poly(siloxane-etherimide) Compositions for Electrical Tracking Resistance

The patent creates a composite material system by combining poly(siloxane-etherimide) base polymer with specific additives including polyesters (such as PBT, PET), fillers (talc, calcium carbonate), and inorganic compounds (boron compounds, zinc compounds). This composite approach allows the material to achieve both high mechanical properties from the base polymer and improved electrical tracking resistance through the synergistic effect of the additives, resolving the contradiction between mechanical strength and electrical tracking resistance.

The patent optimizes the concentration ranges of various additives to achieve the desired electrical tracking resistance while maintaining processability. Specifically, it specifies polyesters at 1-30 wt%, fillers at 1-50 wt%, and inorganic compounds at 1-20 wt% of the total composition. These parameter optimizations ensure that the material achieves CTI rating improvements without excessive viscosity increase or processing difficulty, balancing electrical performance with manufacturing ease.

The patent employs a multi-component additive strategy where different additives serve specific functions: polyesters provide electrical tracking resistance improvement, fillers like talc and calcium carbonate enhance mechanical properties and cost-effectiveness, and inorganic compounds provide additional electrical resistance. This localized functional assignment ensures that each component contributes to specific properties, allowing the material to achieve excellent electrical tracking resistance while maintaining or even improving mechanical properties through the synergistic combination rather than relying on high concentrations of a single additive.