To modify oil or contaminating agent absorbing tendency of a porous sheet material, such as an expanded polytetrafluoroethylene, that is waterproof, moisture vapor transmissive and air permeable.
A method for modifying a property of the porous membrane comprises the steps of providing a uniform precipitated coating 28 of materials selected from a group consisting of a fluorinated urethane polymer and fluorinated acrylic polymer on at least a plurality of portions of the surfaces of the nodes 22 and fibrils 24 defining the pores 26. The precipitated fluorinated urethane polymer material provides oil and contaminating agent resistance of at least a number 6 by AATCC 188 testing and an air permeability of at least 0.20 CFM per square foot by ASTMD 737 testing.
STRUGALSKI GREG
| JPH08506612A | 1996-07-16 |
| WO2000047313A1 | 2000-08-17 |
Hirokazu Ogura
Toshihisa Kurokawa