Patent ID: 7771818

Claim:
A sheet material that is waterproof, moisture vapor transmissive and air permeable, said sheet material comprising: a polymeric membrane having an open pore structure including surfaces defining a plurality of interconnecting pores extending through said membrane and between major sides of said membrane in which the pores have an average pore size, said membrane being made from a material tending to absorb oils and contaminating agents; and a precipitated uniform coating material comprising at least one of fluorinated urethane polymer particles and fluorinated acrylic polymer particles having a particle size of about 1.0 to 10.0 nanometers on at least portions of the surfaces of nodes and fibrils defining the pores in said membrane; said precipitated material provides oil and contaminating agent resistance of at least a number 6 by AATCC 118 testing and said sheet material having an air permeability of at least 0.20 CFM per square foot by ASTM D737 testing and a moisture vapor transmission at a rate of at least 70,000 gr/m 2 /day.