US Patent 7811490 Boron nitride filled PTFE

A composition is provided that, in one aspect, may be used in the production of sealing materials, such as gaskets. The composition includes a polytetraflouroethylene matrix and a Boron Nitride filler. In one aspect, the Boron Nitride filler may be provided as a hexagonal, close-packed, Boron Nitride filler that is homogeneously dispersed within the polytetraflouroethylene matrix. In at least one embodiment, the composition is formed by combining quantities of polytetraflouroethylene, Boron Nitride filler, hydrocarbon liquid, and solvent. The liquid and solvent may be removed through various processes prior to sintering the composition to form a full-density, Boron Nitride filled, polytetraflouroethylene matrix that exhibits improved sealability, greater resistance to permeation, and less color contamination.