Electrostatic silica coating for electric lamps

摘要

A silica powder mixture is disclosed for electrostatic deposition to provide diffuse light from electric lamps. The present powder mixture exhibits improved moisture resistance along with shelf life and comprises in weight proportions approximately 35-65 parts calcined diatomaceous silica, approximately 35-65 parts fumed silica, and approximately 5-15 parts colloidal hydrophobic silica.