| abstract |
The present invention relates to a purification method using a polyimide and / or a polyamide-imide porous membrane excellent in impurity removal performance such as metal, a silylating agent chemical liquid, a film forming material or a liquid as a diffusion agent composition as a retentate, , A method of producing a silylating agent chemical solution, a film forming material or a diffusion agent composition using the purification method, a method of producing a film made of the porous film Media and a filter device comprising the porous film. A method for purifying a liquid as a retentate, which comprises transmitting a part or the whole of the liquid by differential pressure from one side of the polyimide and / or polyamide-imide porous membrane having a communicating hole to the other side, Is a silylating agent chemical liquid, a film forming material, or a refining method which is a diffusing agent composition used for dopant diffusion to a semiconductor substrate. |