Mouldings cpds based on phenolic or melamineresins

摘要

Title compns. contain, as filler, 5-25 wt.% (w.r.t. compn.) of SiO2, Al2O3, B2O3, TiO2, and/or AlF3. The filler(s) used contain =0.1 wt.% of alkali(ne earth). Pptd. SiO2 is esp. sutiable. Used in mfe. of insulating components for electrical switchgear.