PROCESS FOR AFFORDING HYDROPHILIC PROPERTY TO HYDROPHOBIC POROUS FILM

摘要

PURPOSE:To afford hydrophilic property to hydrophobic porous film without accompanying decrease of water permeability with the lapse of time by treating hydrophobic porous film with corona discharge at =80 deg.C, and treating further for =1min with soln. of polyol. CONSTITUTION:Hydrophobic porous film which is impermeable as it is for liquid having high surface tension such as aq. soln. unless high pressure is applied, is used. The film is treated with corona discharge of 1-20W/m2min output for 0.1-1,000sec at =80 deg.C. Thus, hydrophilic groups such as OH, CO, COOH, etc. on the surface of fine pores. Within 3hr after this treatment, the film is treated with polyol having 90-10,000 mol.wt. such as polyethylene glycol. Suitable concn. of the polyol is 10-80%, which is dissolved in a solvent having low viscosity and low surface tension such as alcohol or acetone.