| abstract |
Oleophobic and hydrophobic filters for filter venting applications are made by forming a polydimethylsiloxane coating on the surface of a filtration substrate. The filters have high water penetration pressures and high air permeabilities. The coatings are formed by polymerizing vinyl terminated siloxane with a crosslinker such as hydrosilicone in the presence of a catalyst. Alternatively, the coatings can be formed by heat curing after exposing the substrate to methyl silicone and crosslinking at high temperature. |