Patent ID: 8419961

Claim:
A method for preparing an oil gas separation membrane for separating dissolved fault gases from gas-containing dielectric fluid of an electric system, comprising the steps of: (a) preparing a bulk polymer membrane with a thickness between 0.01-0.5 mm from a polymer material wherein said bulk polymer membrane is sanded uniformly by #600-1500 abrasive paper, and etching said bulk polymer membrane for 1-15 minutes with an etching solution formulated at a weight ratio of sodium 1 part:Naphthalene 4 parts:Tetrahydrofuran 3 parts, wherein said bulk polymer membrane is made of material selected from the group consisting of poly(tetrafluoroethylene), poly(tetrafluoroethylene-co-hexafluoropropylene), poly(vinylidene fluoride), and poly(tetrafluoroethylene-co-perfluoro alkoxy vinyl ether); (b) providing a metal frit disk made of metal selected from the group consisting of stainless steel, copper, and nickel, with a metal frit thickness between 1-5 mm, porosity greater than 20%, and pore size between 0.001-0.1 mm; (c) preparing a gas permeable adhesive which is an amorphous polymer selected from the group consisting of an organic solution of TFE/PFD copolymer, an aqueous solution of PTFE or PFEP particulate dispersion, and an organic solution of PTFE or PFEP particulate dispersion with 0.05-5 μm in particle size; and (d) bonding said bulk polymer membrane and said metal frit disk with said gas permeable adhesive, and baking said bonded membrane at a predetermined temperature.